diff --git a/app/Http/Controllers/Api/ProjectController.php b/app/Http/Controllers/Api/ProjectController.php
index 2d595d01d..2e8dc9445 100755
--- a/app/Http/Controllers/Api/ProjectController.php
+++ b/app/Http/Controllers/Api/ProjectController.php
@@ -3851,6 +3851,11 @@ class ProjectController extends AbstractController
         $type = trim(Request::input('type'));
         $data = Request::input('data', []);
 
+        // 验证建议类型
+        if (!in_array($type, ProjectTaskAiEvent::getEventTypes())) {
+            return Base::retError('无效的建议类型');
+        }
+
         // 验证任务
         $task = ProjectTask::userTask($taskId);
         if (!$task) {
@@ -3884,6 +3889,13 @@ class ProjectController extends AbstractController
             case ProjectTaskAiEvent::EVENT_SUBTASKS:
                 // 创建子任务
                 $subtasks = $result['content'] ?? [];
+                // 检查子任务数量限制
+                $existingCount = ProjectTask::where('parent_id', $task->id)
+                    ->whereNull('deleted_at')
+                    ->count();
+                if ($existingCount + count($subtasks) > 50) {
+                    return Base::retError('子任务数量超过限制（最多50个）');
+                }
                 \DB::transaction(function () use ($task, $subtasks) {
                     foreach ($subtasks as $name) {
                         ProjectTask::addTask([
@@ -3963,12 +3975,27 @@ class ProjectController extends AbstractController
         $msgId = intval(Request::input('msg_id'));
         $type = trim(Request::input('type'));
 
+        // 验证建议类型
+        if (!in_array($type, ProjectTaskAiEvent::getEventTypes())) {
+            return Base::retError('无效的建议类型');
+        }
+
         // 验证任务
         $task = ProjectTask::userTask($taskId);
         if (!$task) {
             return Base::retError('任务不存在或无权限');
         }
 
+        // 验证事件记录存在
+        $event = ProjectTaskAiEvent::where('task_id', $taskId)
+            ->where('event_type', $type)
+            ->where('msg_id', $msgId)
+            ->first();
+
+        if (!$event || $event->status !== ProjectTaskAiEvent::STATUS_COMPLETED) {
+            return Base::retError('建议不存在或已处理');
+        }
+
         // 更新消息状态
         if ($msgId > 0 && $task->dialog_id) {
             AiTaskSuggestion::updateMessageStatus($msgId, $task->dialog_id, $type, 'dismissed');
diff --git a/app/Module/AiTaskSuggestion.php b/app/Module/AiTaskSuggestion.php
index 9680ba7b8..efc329f95 100644
--- a/app/Module/AiTaskSuggestion.php
+++ b/app/Module/AiTaskSuggestion.php
@@ -47,8 +47,8 @@ class AiTaskSuggestion
                 return !$hasOwner;
 
             case ProjectTaskAiEvent::EVENT_SIMILAR:
-                // 始终执行
-                return true;
+                // 向量搜索暂未实现，跳过
+                return false;
 
             default:
                 return false;
@@ -164,17 +164,29 @@ class AiTaskSuggestion
         }
     }
 
+    /**
+     * 转义用户输入以防止 Prompt 注入
+     */
+    private static function escapeUserInput(string $input): string
+    {
+        // 移除可能影响 AI Prompt 解析的特殊字符
+        $input = str_replace(['```', '---', '==='], '', $input);
+        // 截断过长的输入
+        return mb_substr(trim($input), 0, 500);
+    }
+
     /**
      * 构建描述生成 Prompt
      */
     private static function buildDescriptionPrompt(ProjectTask $task): string
     {
-        $projectName = $task->project->name ?? '未知项目';
+        $taskName = self::escapeUserInput($task->name);
+        $projectName = self::escapeUserInput($task->project->name ?? '未知项目');
 
         return <<<PROMPT
 你是一个专业的项目管理助手。请根据以下任务标题，生成结构化的任务描述。
 
-任务标题：{$task->name}
+任务标题：{$taskName}
 所属项目：{$projectName}
 
 请按以下格式生成任务描述（使用 Markdown）：
@@ -198,12 +210,13 @@ PROMPT;
      */
     private static function buildSubtasksPrompt(ProjectTask $task): string
     {
-        $content = $task->content ?? '';
+        $taskName = self::escapeUserInput($task->name);
+        $content = self::escapeUserInput($task->content ?? '');
 
         return <<<PROMPT
 你是一个专业的项目管理助手。请将以下任务拆分为可执行的子任务。
 
-任务标题：{$task->name}
+任务标题：{$taskName}
 任务描述：{$content}
 
 请返回 3-5 个子任务，每行一个，格式如下：
@@ -226,9 +239,11 @@ PROMPT;
     {
         $membersText = '';
         foreach ($members as $member) {
-            $membersText .= "- {$member['nickname']}（ID:{$member['userid']}）";
+            $nickname = self::escapeUserInput($member['nickname']);
+            $membersText .= "- {$nickname}（ID:{$member['userid']}）";
             if (!empty($member['profession'])) {
-                $membersText .= "，职位：{$member['profession']}";
+                $profession = self::escapeUserInput($member['profession']);
+                $membersText .= "，职位：{$profession}";
             }
             $membersText .= "，进行中任务：{$member['in_progress_count']}个";
             $membersText .= "，近期完成：{$member['completed_count']}个";
@@ -238,11 +253,14 @@ PROMPT;
             $membersText .= "\n";
         }
 
+        $taskName = self::escapeUserInput($task->name);
+        $taskContent = self::escapeUserInput($task->content ?? '');
+
         return <<<PROMPT
 你是一个专业的项目管理助手。请根据任务内容和团队成员情况，推荐最合适的负责人。
 
-任务标题：{$task->name}
-任务描述：{$task->content}
+任务标题：{$taskName}
+任务描述：{$taskContent}
 
 团队成员：
 {$membersText}
@@ -552,7 +570,10 @@ MD;
      */
     public static function updateMessageStatus(int $msgId, int $dialogId, string $type, string $status): void
     {
-        $msg = WebSocketDialogMsg::find($msgId);
+        // 验证消息存在且属于指定对话
+        $msg = WebSocketDialogMsg::where('id', $msgId)
+            ->where('dialog_id', $dialogId)
+            ->first();
         if (!$msg) {
             return;
         }
diff --git a/app/Tasks/AiTaskAnalyzeTask.php b/app/Tasks/AiTaskAnalyzeTask.php
index e72f03235..75a83d08c 100644
--- a/app/Tasks/AiTaskAnalyzeTask.php
+++ b/app/Tasks/AiTaskAnalyzeTask.php
@@ -53,8 +53,16 @@ class AiTaskAnalyzeTask extends AbstractTask
                 continue;
             }
 
-            // 标记为处理中
-            $event->markProcessing();
+            // 使用原子操作标记为处理中（防止并发重复处理）
+            $updated = ProjectTaskAiEvent::where('id', $event->id)
+                ->whereIn('status', [ProjectTaskAiEvent::STATUS_PENDING, ProjectTaskAiEvent::STATUS_FAILED])
+                ->update(['status' => ProjectTaskAiEvent::STATUS_PROCESSING]);
+
+            if (!$updated) {
+                // 已被其他进程处理
+                continue;
+            }
+            $event->status = ProjectTaskAiEvent::STATUS_PROCESSING;
 
             try {
                 // 检查是否满足执行条件
diff --git a/resources/assets/js/store/actions.js b/resources/assets/js/store/actions.js
index deb37de51..718e0d896 100644
--- a/resources/assets/js/store/actions.js
+++ b/resources/assets/js/store/actions.js
@@ -5229,15 +5229,9 @@ export default {
      * 采纳 AI 建议
      */
     applyAiSuggestion({}, params) {
-        return new Promise((resolve, reject) => {
-            this.dispatch('call', {
-                url: 'project/task/ai-apply',
-                data: params,
-            }).then(result => {
-                resolve(result);
-            }).catch(e => {
-                reject(e);
-            });
+        return this.dispatch('call', {
+            url: 'project/task/ai-apply',
+            data: params,
         });
     },
 
@@ -5245,15 +5239,9 @@ export default {
      * 忽略 AI 建议
      */
     dismissAiSuggestion({}, params) {
-        return new Promise((resolve, reject) => {
-            this.dispatch('call', {
-                url: 'project/task/ai-dismiss',
-                data: params,
-            }).then(result => {
-                resolve(result);
-            }).catch(e => {
-                reject(e);
-            });
+        return this.dispatch('call', {
+            url: 'project/task/ai-dismiss',
+            data: params,
         });
     }