diff --git a/nexus/Install/Install.php b/nexus/Install/Install.php
index 0f6b23f2..f982680c 100644
--- a/nexus/Install/Install.php
+++ b/nexus/Install/Install.php
@@ -6,11 +6,11 @@ use Nexus\Database\DB;
 
 class Install
 {
-    private $currentStep;
+    protected $currentStep;
 
-    private $minimumPhpVersion = '7.2.0';
+    protected $minimumPhpVersion = '7.2.0';
 
-    private $progressKeyPrefix = '__step';
+    protected $progressKeyPrefix = '__step';
 
     protected $steps = ['环境检测', '添加 .env 文件', '创建数据表', '导入数据', '创建管理员账号'];
 
@@ -97,7 +97,6 @@ class Install
 
     public function listExistsTable()
     {
-        dbconn(false, false);
         $sql = 'show tables';
         $res = sql_query($sql);
         $data = [];
diff --git a/nexus/Install/Update.php b/nexus/Install/Update.php
new file mode 100644
index 00000000..e1b940e4
--- /dev/null
+++ b/nexus/Install/Update.php
@@ -0,0 +1,77 @@
+<?php
+
+namespace Nexus\Install;
+
+class Update extends Install
+{
+
+    protected $steps = ['环境检测', '添加 .env 文件', '修改&创建数据表', '导入数据'];
+
+    protected $initializeTables = [
+        'adminpanel', 'agent_allowed_exception', 'agent_allowed_family', 'allowedemails', 'audiocodecs', 'avps', 'bannedemails', 'categories',
+        'caticons', 'codecs', 'countries', 'downloadspeed', 'faq', 'isp', 'language', 'media', 'modpanel', 'processings', 'rules', 'schools',
+        'searchbox', 'secondicons', 'sources', 'standards', 'stylesheets', 'sysoppanel', 'teams', 'torrents_state', 'uploadspeed', 'agent_allowed_family',
+    ];
+
+
+    public function getLogFile()
+    {
+        return sprintf('%s/nexus_update_%s.log', sys_get_temp_dir(), date('Ymd'));
+    }
+
+    public function getUpdateDirectory()
+    {
+        return ROOT_PATH . 'public/update';
+    }
+
+
+    public function listShouldAlterTableTableRows()
+    {
+        $tables = $this->listExistsTable();
+        $data = [];
+        foreach ($tables as $table) {
+            $sql = "desc $table";
+            $res = sql_query($sql);
+            while ($row = mysql_fetch_assoc($res)) {
+                if ($row['Type'] == 'datetime' && $row['Default'] == '0000-00-00 00:00:00') {
+                    $data[$table][] = $row['Field'];
+                    $data[] = [
+                        'label' => "$table." . $row['Field'],
+                        'required' => 'default null',
+                        'current' => '0000-00-00 00:00:00',
+                        'result' => 'NO',
+                    ];
+                }
+            }
+        }
+        return $data;
+    }
+
+
+    public function importInitialData($sqlFile = '')
+    {
+        if (empty($sqlFile)) {
+            $sqlFile = ROOT_PATH . '_db/dbstructure_v1.6.sql';
+        }
+        $string = file_get_contents($sqlFile);
+        $pattern = "/INSERT INTO `(\w+)` VALUES \(.*\);\n/i";
+        preg_match_all($pattern, $string, $matches, PREG_SET_ORDER);
+        foreach ($matches as $match) {
+            $table = $match[1];
+            $sql = trim($match[0]);
+            if (!in_array($table, $this->initializeTables)) {
+                continue;
+            }
+            //if table not empty, skip
+            $count = get_row_count($table);
+            if ($count > 0) {
+                $this->doLog("[IMPORT DATA] $table, not empty, skip");
+                continue;
+            }
+            $this->doLog("[IMPORT DATA] $table, $sql");
+            sql_query("truncate table $table");
+            sql_query($sql);
+        }
+        return true;
+    }
+}
\ No newline at end of file
diff --git a/nexus/Install/update/update.php b/nexus/Install/update/update.php
new file mode 100644
index 00000000..4758a58c
--- /dev/null
+++ b/nexus/Install/update/update.php
@@ -0,0 +1,219 @@
+<?php
+ini_set('error_reporting', E_ALL);
+ini_set('display_errors', 0);
+$rootpath = dirname(dirname(__DIR__)) . '/';
+define('ROOT_PATH', $rootpath);
+$isPost = $_SERVER['REQUEST_METHOD'] == 'POST';
+require $rootpath . 'vendor/autoload.php';
+require $rootpath . 'include/globalfunctions.php';
+require $rootpath . 'include/functions.php';
+require $rootpath . 'nexus/Database/helpers.php';
+
+$update = new \Nexus\Install\Update();
+$currentStep = $update->currentStep();
+$maxStep = $update->maxStep();
+if (!$update->canAccessStep($currentStep)) {
+    $update->gotoStep(1);
+}
+$error = $copy = '';
+
+//step 1
+if ($currentStep == 1) {
+    $requirements = $update->listRequirementTableRows();
+    $pass = $requirements['pass'];
+    if ($isPost) {
+        $update->nextStep();
+    }
+}
+
+if ($currentStep == 2) {
+    $envExampleFile = "$rootpath.env.example";
+    $envExampleData = readEnvFile($envExampleFile);
+    $envFormControls = $update->listEnvFormControls();
+    $newData = array_column($envFormControls, 'value', 'name');
+    while ($isPost) {
+        try {
+            $update->createEnvFile($_POST);
+            $update->nextStep();
+        } catch (\Exception $exception) {
+            $error = $exception->getMessage();
+            break;
+        }
+        break;
+    }
+    $tableRows = [
+        [
+            'label' => '.env.example',
+            'required' => 'exists && readable',
+            'current' => $envExampleFile,
+            'result' =>  $update->yesOrNo(file_exists($envExampleFile) && is_readable($envExampleFile)),
+        ],
+    ];
+    $fails = array_filter($tableRows, function ($value) {return $value['result'] == 'NO';});
+    $pass = empty($fails);
+}
+
+if ($currentStep == 3) {
+    $pass = true;
+    $shouldCreateTable = $update->listShouldCreateTable();
+    while ($isPost) {
+        try {
+            $update->createTable($shouldCreateTable);
+            $update->nextStep();
+        } catch (\Exception $exception) {
+            $error = $exception->getMessage();
+            break;
+        }
+        break;
+    }
+}
+
+//if ($currentStep == 4) {
+//    $pass = true;
+//    while (true) {
+//        $shouldAlterTable = listShouldAlterTable();
+//        if ($isPost) {
+//            if (!empty($shouldAlterTable)) {
+//                try {
+//                    sql_query('SET sql_mode=(SELECT REPLACE(@@sql_mode,"NO_ZERO_DATE", ""));');
+//                    foreach ($shouldAlterTable as $table => $fields) {
+//                        $sqlAlter = "alter table $table";
+//                        $sqlUpdate = "update $table";
+//                        $updateWhere = [];
+//                        foreach ($fields as $field) {
+//                            $sqlAlter .= " modify $field datetime default null,";
+//                            $sqlUpdate .= " set $field = null,";
+//                            $updateWhere[] = "$field = '0000-00-00 00:00:00'";
+//                        }
+//                        $sqlAlter = rtrim($sqlAlter, ',');
+//                        $sqlUpdate = rtrim($sqlUpdate, ',') . " where " . implode(' or ', $updateWhere);
+//                        sql_query($sqlUpdate);
+//                        sql_query($sqlAlter);
+//                    }
+//                } catch (\Exception $e) {
+//                    $error = $e->getMessage();
+//                    break;
+//                }
+//            }
+//            goStep($currentStep + 1);
+//        }
+//        break;
+//    }
+//}
+
+if ($currentStep == 4) {
+    $settingTableRows = $update->listSettingTableRows();
+    $settings = $settingTableRows['settings'];
+    $symbolicLinks = $settingTableRows['symbolic_links'];
+    $tableRows = $settingTableRows['table_rows'];
+    $pass = $settingTableRows['pass'];
+    while ($isPost) {
+        try {
+            $update->createSymbolicLinks($symbolicLinks);
+            $update->saveSettings($settings);
+            $update->importInitialData();
+            $update->nextStep();
+        } catch (\Exception $e) {
+            $error = $e->getMessage();
+            break;
+        }
+        break;
+    }
+}
+
+if ($currentStep == 5) {
+    if ($isPost) {
+        try {
+            $update->createAdministrator($_POST['username'], $_POST['email'], $_POST['password'], $_POST['confirm_password']);
+            $update->nextStep();
+        } catch (\Exception $exception) {
+            $error = $exception->getMessage();
+        }
+    }
+    $pass = true;
+    $userFormControls = [
+        ['label' => '用户名', 'name' => 'username', 'value' => $_POST['username'] ?? ''],
+        ['label' => '邮箱', 'name' => 'email', 'value' => $_POST['email'] ?? ''],
+        ['label' => '密码', 'name' => 'password', 'value' => $_POST['password'] ?? ''],
+        ['label' => '确认密码', 'name' => 'confirm_password', 'value' => $_POST['confirm_password'] ?? ''],
+    ];
+}
+?>
+
+<!doctype html>
+<html lang="en">
+<head>
+    <!-- Required meta tags -->
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+    <link href="https://unpkg.com/tailwindcss@^1.0/dist/tailwind.min.css" rel="stylesheet">
+    <title>Install NexusPHP | step <?php echo $currentStep?></title>
+</head>
+<body>
+<div class="container mx-auto">
+    <?php echo $update->renderSteps()?>
+    <div class="mt-10">
+        <form method="post" action="<?php echo getBaseUrl() . '?step=' . $currentStep?>">
+            <input type="hidden" name="step" value="<?php echo $currentStep?>">
+            <?php
+            echo'<div class="step-' . $currentStep . ' text-center">';
+            $header = ['项目', '要求', '当前', '结果'];
+            if ($currentStep == 1) {
+                echo $update->renderTable($header, $requirements['table_rows']);
+            } elseif ($currentStep == 2) {
+                echo $update->renderTable($header, $tableRows);
+                echo '<div class="text-gray-700 p-4 text-red-400">若 Redis 不启用，相关项目留空</div>';
+                echo $update->renderForm($envFormControls);
+
+            } elseif ($currentStep == 3) {
+                echo '<h1 class="mb-4 text-lg font-bold">需要新建以下数据表</h1>';
+                if (empty($shouldCreateTable)) {
+                    echo '<div class="text-green-600 text-center">恭喜，需要的表均已创建!</div>';
+                } else {
+                    echo sprintf('<div class="h-64 text-left inline-block w-2/3"><code class="bolck w-px-100">%s</code></div>', implode(', ', array_keys($shouldCreateTable)));
+                }
+            } elseif ($currentStep == 4) {
+                echo $update->renderTable($header, $tableRows);
+                echo '<div class="text-blue-500 pt-10">';
+                echo sprintf('这一步会把 <code>%s</code> 的数据合并到 <code>%s</code>, 然后插入数据库中。', $tableRows[1]['label'], $tableRows[0]['label']);
+                echo '</div>';
+            } elseif ($currentStep == 5) {
+                echo $update->renderForm($userFormControls, '1/3', '1/4', '3/4');
+            } elseif ($currentStep > $maxStep) {
+                echo '<div class="text-green-900 text-6xl p-10">恭喜，一切就绪！</div>';
+                echo '<div class="mb-6">有问题可查阅安装日志：<code>' . $update->getLogFile() . '</code></div>';
+                echo '<div class="text-red-500">为安全起见，请删除以下目录</div>';
+                echo '<div class="text-red-500"><code>' . $update->getInsallDirectory() . '</code></div>';
+            }
+            echo'</div>';
+
+            if (!empty($error)) {
+                echo sprintf('<div class="text-center text-red-500 p-4">Error: %s</div>', nl2br($error));
+                unset($error);
+            }
+            if (!empty($copy)) {
+                echo sprintf('<div class="text-center"><textarea class="w-1/2 h-40 border">%s</textarea></div>', $copy);
+                unset($copy);
+            }
+            ?>
+            <div class="mt-10 text-center">
+                <button class="bg-blue-500 p-2 m-4 text-white rounded" type="button" onclick="goBack()">上一步</button>
+                <?php if ($currentStep <= $maxStep) {?>
+                    <button class="bg-blue-<?php echo $pass ? 500 : 200;?> p-2 m-4 text-white rounded" type="submit" <?php echo $pass ? '' : 'disabled';?>>下一步</button>
+                <?php } else {?>
+                    <a class="bg-blue-500 p-2 m-4 text-white rounded" href="<?php echo getSchemaAndHttpHost()?>">回首页</a>
+                <?php }?>
+            </div>
+        </form>
+    </div>
+</div>
+<div class="mt-10 text-center">
+    欢迎使用 NexusPHP 升级程序(v1.5 ~ v1.6)，如有疑问，点击<a href="http://nexusphp.org/" target="_blank" class="text-blue-500 p-1">这里</a>获取帮助。
+</div>
+</body>
+<script>
+    function goBack() {
+        window.location.search="step=<?php echo $currentStep == 1 ? 1 : $currentStep - 1?>"
+    }
+</script>
+</html>
\ No newline at end of file