diff --git a/src/app/api/webhook/projects/route.ts b/src/app/api/webhook/projects/route.ts
index 56d99a4..ddb1844 100644
--- a/src/app/api/webhook/projects/route.ts
+++ b/src/app/api/webhook/projects/route.ts
@@ -7,6 +7,80 @@ import {
   type ProjectInput,
 } from '@/lib/validations'
 
+/**
+ * 多级去重策略：查找已存在的项目
+ *
+ * 优先级：
+ * 1. GitHub URL 完全匹配（最准确）
+ * 2. Website URL 完全匹配
+ * 3. slug 匹配（兜底）
+ *
+ * @param projectData - 项目数据
+ * @returns 已存在的项目，如果不存在则返回 null
+ */
+async function findExistingProject(projectData: ProjectInput) {
+  // 优先级1: 通过 GitHub URL 匹配
+  const githubLink = projectData.links.find((link) => link.type === 'GITHUB')
+  if (githubLink) {
+    const existingByGithub = await prisma.externalLink.findFirst({
+      where: {
+        type: 'GITHUB',
+        url: githubLink.url,
+      },
+      include: {
+        project: true,
+      },
+    })
+
+    if (existingByGithub) {
+      console.log(
+        `[Webhook] Found existing project by GitHub URL: ${githubLink.url}`
+      )
+      return existingByGithub.project
+    }
+  }
+
+  // 优先级2: 通过 Website URL 匹配
+  const websiteLink = projectData.links.find(
+    (link) => link.type === 'WEBSITE'
+  )
+  if (websiteLink) {
+    const existingByWebsite = await prisma.externalLink.findFirst({
+      where: {
+        type: 'WEBSITE',
+        url: websiteLink.url,
+      },
+      include: {
+        project: true,
+      },
+    })
+
+    if (existingByWebsite) {
+      console.log(
+        `[Webhook] Found existing project by Website URL: ${websiteLink.url}`
+      )
+      return existingByWebsite.project
+    }
+  }
+
+  // 优先级3: 通过 slug 匹配（兜底）
+  const slug =
+    projectData.nameEn?.toLowerCase().replace(/\s+/g, '-') ||
+    projectData.name.toLowerCase().replace(/\s+/g, '-')
+
+  const existingBySlug = await prisma.project.findUnique({
+    where: { slug },
+  })
+
+  if (existingBySlug) {
+    console.log(`[Webhook] Found existing project by slug: ${slug}`)
+    return existingBySlug
+  }
+
+  console.log(`[Webhook] No existing project found, will create new one`)
+  return null
+}
+
 export async function POST(request: NextRequest) {
   const startTime = Date.now()
 
@@ -77,6 +151,9 @@ export async function POST(request: NextRequest) {
       try {
         const validProject = projectValidation.data as ProjectInput
 
+        // 多级去重：查找已存在的项目
+        const existingProject = await findExistingProject(validProject)
+
         // Upsert tags
         const tagConnections = await Promise.all(
           validProject.tags.map(async (tag) => {
@@ -101,13 +178,21 @@ export async function POST(request: NextRequest) {
           validProject.nameEn?.toLowerCase().replace(/\s+/g, '-') ||
           validProject.name.toLowerCase().replace(/\s+/g, '-')
 
-        // Upsert project
-        const existingProject = await prisma.project.findUnique({
-          where: { slug },
-        })
-
         if (existingProject) {
           // Update existing project
+          const matchMethod = existingProject.slug === slug
+            ? 'slug'
+            : validProject.links.some(
+                (l) =>
+                  existingProject.links.some((el) => el.url === l.url)
+              )
+            ? 'url'
+            : 'unknown'
+
+          console.log(
+            `[Webhook] Updating project "${validProject.name}" (matched by ${matchMethod}, id: ${existingProject.id})`
+          )
+
           await prisma.project.update({
             where: { id: existingProject.id },
             data: {
@@ -142,6 +227,10 @@ export async function POST(request: NextRequest) {
           results.updated++
         } else {
           // Create new project
+          console.log(
+            `[Webhook] Creating new project "${validProject.name}" (slug: ${slug})`
+          )
+
           await prisma.project.create({
             data: {
               name: validProject.name,