diff --git a/services.py b/services.py
index 1f68ce0..376d6b8 100644
--- a/services.py
+++ b/services.py
@@ -134,6 +134,14 @@ class TranslationService:
         pages = self.extract_pdf_text(pdf_path)
         total_pages = len(pages)
         
+        # 检查是否有可翻译内容
+        total_text = sum(len(p['text']) for p in pages)
+        if total_pages == 0 or total_text < 10:
+            error_msg = "PDF无法提取文本内容。可能原因：\n1. PDF是扫描版（图像形式），需要OCR处理\n2. PDF为空或加密\n请使用包含可提取文本的PDF文件。"
+            if progress_callback:
+                progress_callback(0, 0, error_msg)
+            raise ValueError(error_msg)
+        
         if progress_callback:
             progress_callback(0, total_pages, "开始翻译...")