diff --git a/packages/parser/src/formats/shuakami-qq-exporter-chunked.ts b/packages/parser/src/formats/shuakami-qq-exporter-chunked.ts
index 46c1f562..7dcc9cb4 100644
--- a/packages/parser/src/formats/shuakami-qq-exporter-chunked.ts
+++ b/packages/parser/src/formats/shuakami-qq-exporter-chunked.ts
@@ -51,6 +51,7 @@ export const feature: FormatFeature = {
     // V5 使用 metadata.format，0.1.x 将格式标识移至 chunked.format。
     head: [/"format"\s*:\s*"chunked-jsonl"/, /"chunked"\s*:\s*\{[^{}]*"format"\s*:\s*"jsonl"/],
     filename: [/^manifest\.json$/i],
+    filenameFallbackPatterns: [/"chunked"\s*:\s*\{[\s\S]*?"format"\s*:\s*"jsonl"/],
     requiredFields: ['metadata', 'chatInfo'],
   },
 }
diff --git a/packages/parser/src/formats/shuakami-qq-exporter.test.ts b/packages/parser/src/formats/shuakami-qq-exporter.test.ts
index 3459873e..581b73e9 100644
--- a/packages/parser/src/formats/shuakami-qq-exporter.test.ts
+++ b/packages/parser/src/formats/shuakami-qq-exporter.test.ts
@@ -57,10 +57,10 @@ function systemMessage(text: string): unknown {
   }
 }
 
-async function parseContent(content: string): Promise<ParseResult> {
+async function parseContent(content: string, filename = 'qce-export.json'): Promise<ParseResult> {
   const dir = mkdtempSync(join(tmpdir(), 'chatlab-qce-parser-'))
   try {
-    const filePath = join(dir, 'qce-export.json')
+    const filePath = join(dir, filename)
     writeFileSync(filePath, content, 'utf-8')
     assert.equal(detectFormat(filePath)?.id, 'shuakami-qq-exporter')
     return await parseFileSync(filePath)
@@ -70,6 +70,19 @@ async function parseContent(content: string): Promise<ParseResult> {
 }
 
 describe('shuakami-qq-exporter parser', () => {
+  it('does not misclassify a single-file export renamed to manifest.json', async () => {
+    const result = await parseContent(
+      makeExport({
+        chatInfoType: 'group',
+        senders: [{ uid: 'u_100', name: 'Alice' }],
+        messages: [textMessage('100', 'Alice', 'hello')],
+      }),
+      'manifest.json'
+    )
+
+    assert.equal(result.messages.length, 1)
+  })
+
   it('prefers chatInfo.type and skips placeholder system senders', async () => {
     const content = makeExport({
       chatInfoType: 'private',
diff --git a/packages/parser/src/sniffer.ts b/packages/parser/src/sniffer.ts
index 40ec1b94..d7b5bb19 100644
--- a/packages/parser/src/sniffer.ts
+++ b/packages/parser/src/sniffer.ts
@@ -43,6 +43,18 @@ function matchFilenameSignatures(filePath: string, patterns: RegExp[]): boolean
   return patterns.some((pattern) => pattern.test(filename))
 }
 
+/**
+ * 文件名只能作为补充特征；需要全文确认时再读取完整文件。
+ */
+function matchFilenameFallbackPatterns(filePath: string, patterns: RegExp[]): boolean {
+  try {
+    const content = fs.readFileSync(filePath, 'utf-8')
+    return patterns.every((pattern) => pattern.test(content))
+  } catch {
+    return false
+  }
+}
+
 /**
  * 检查必需字段是否存在
  */
@@ -202,6 +214,12 @@ export class FormatSniffer {
       }
     }
 
+    if (!headMatch && filenameMatch && signatures.filenameFallbackPatterns) {
+      if (!filePath || !matchFilenameFallbackPatterns(filePath, signatures.filenameFallbackPatterns)) {
+        return false
+      }
+    }
+
     // 4. 检查必需字段（如果定义了）
     if (signatures.requiredFields && signatures.requiredFields.length > 0) {
       if (!matchRequiredFields(headContent, signatures.requiredFields)) {
diff --git a/packages/parser/src/types.ts b/packages/parser/src/types.ts
index 436faccb..192f2586 100644
--- a/packages/parser/src/types.ts
+++ b/packages/parser/src/types.ts
@@ -70,6 +70,8 @@ export interface FormatSignatures {
   head?: RegExp[]
   /** 文件名正则匹配（任意一个匹配即可，作为文件头匹配的补充） */
   filename?: RegExp[]
+  /** 文件名补充匹配时，必须在完整文件中命中的模式 */
+  filenameFallbackPatterns?: RegExp[]
   /** 必须存在的 JSON 字段路径 */
   requiredFields?: string[]
   /** 字段值模式匹配 */