diff --git a/backend_api_python/app/data_sources/polymarket.py b/backend_api_python/app/data_sources/polymarket.py
index 4eac4c6..3f2a64e 100644
--- a/backend_api_python/app/data_sources/polymarket.py
+++ b/backend_api_python/app/data_sources/polymarket.py
@@ -262,18 +262,26 @@ class PolymarketDataSource:
                 cur.close()
                 
                 if rows:
-                    return [{
-                        "market_id": str(row.get('market_id') or ''),
-                        "question": row.get('question') or '',
-                        "category": row.get('category') or 'other',
-                        "current_probability": float(row.get('current_probability') or 0),
-                        "volume_24h": float(row.get('volume_24h') or 0),
-                        "liquidity": float(row.get('liquidity') or 0),
-                        "end_date_iso": row.get('end_date_iso'),
-                        "status": row.get('status') or 'active',
-                        "outcome_tokens": row.get('outcome_tokens') if row.get('outcome_tokens') else {},
-                        "polymarket_url": f"https://polymarket.com/event/{row.get('market_id') or ''}"
-                    } for row in rows]
+                    result = []
+                    for row in rows:
+                        market_id = str(row.get('market_id') or '')
+                        slug = row.get('slug')
+                        # 确保使用正确的URL构建方法
+                        polymarket_url = self._build_polymarket_url(slug, market_id)
+                        result.append({
+                            "market_id": market_id,
+                            "question": row.get('question') or '',
+                            "category": row.get('category') or 'other',
+                            "current_probability": float(row.get('current_probability') or 0),
+                            "volume_24h": float(row.get('volume_24h') or 0),
+                            "liquidity": float(row.get('liquidity') or 0),
+                            "end_date_iso": row.get('end_date_iso'),
+                            "status": row.get('status') or 'active',
+                            "outcome_tokens": row.get('outcome_tokens') if row.get('outcome_tokens') else {},
+                            "polymarket_url": polymarket_url,
+                            "slug": slug if slug and not str(slug).isdigit() else None
+                        })
+                    return result
             
             return None
         except Exception as e:
diff --git a/backend_api_python/app/routes/polymarket.py b/backend_api_python/app/routes/polymarket.py
index c8952e4..341f3b4 100644
--- a/backend_api_python/app/routes/polymarket.py
+++ b/backend_api_python/app/routes/polymarket.py
@@ -160,13 +160,20 @@ def get_markets():
             opportunity_markets = markets[:min(limit, len(markets))]
         
         # 排序和筛选
+        # 辅助函数：安全获取 ai_analysis 数据（处理 None 情况）
+        def safe_get_ai_analysis(market, key, default=0):
+            ai_analysis = market.get('ai_analysis')
+            if ai_analysis is None:
+                return default
+            return ai_analysis.get(key, default) or default
+        
         if sort_by == "ai_score":
             # 按AI机会评分排序（高概率/高回报比优先）
             opportunity_markets.sort(
                 key=lambda x: (
-                    x.get('ai_analysis', {}).get('opportunity_score', 0) or 0,
-                    abs(x.get('ai_analysis', {}).get('divergence', 0) or 0),  # 差异越大越好
-                    x.get('ai_analysis', {}).get('confidence_score', 0) or 0  # 置信度越高越好
+                    safe_get_ai_analysis(x, 'opportunity_score', 0),
+                    abs(safe_get_ai_analysis(x, 'divergence', 0)),  # 差异越大越好
+                    safe_get_ai_analysis(x, 'confidence_score', 0)  # 置信度越高越好
                 ),
                 reverse=True
             )
@@ -174,8 +181,8 @@ def get_markets():
             # 高概率机会：AI预测概率 > 市场概率 + 10%
             opportunity_markets.sort(
                 key=lambda x: (
-                    x.get('ai_analysis', {}).get('ai_predicted_probability', 0) or 0,
-                    x.get('ai_analysis', {}).get('confidence_score', 0) or 0
+                    safe_get_ai_analysis(x, 'ai_predicted_probability', 0),
+                    safe_get_ai_analysis(x, 'confidence_score', 0)
                 ),
                 reverse=True
             )
@@ -183,9 +190,9 @@ def get_markets():
             # 高回报比机会：AI与市场差异大且置信度高
             opportunity_markets.sort(
                 key=lambda x: (
-                    abs(x.get('ai_analysis', {}).get('divergence', 0) or 0) * 
-                    (x.get('ai_analysis', {}).get('confidence_score', 0) or 0) / 100,
-                    x.get('ai_analysis', {}).get('opportunity_score', 0) or 0
+                    abs(safe_get_ai_analysis(x, 'divergence', 0)) * 
+                    safe_get_ai_analysis(x, 'confidence_score', 0) / 100,
+                    safe_get_ai_analysis(x, 'opportunity_score', 0)
                 ),
                 reverse=True
             )
diff --git a/backend_api_python/app/services/market_data_collector.py b/backend_api_python/app/services/market_data_collector.py
index 094cd97..3f55ec6 100644
--- a/backend_api_python/app/services/market_data_collector.py
+++ b/backend_api_python/app/services/market_data_collector.py
@@ -1242,6 +1242,18 @@ class MarketDataCollector:
                 market_id = market_data.get('market_id')
                 if market_id and market_id not in seen:
                     seen.add(market_id)
+                    # 构建正确的 Polymarket URL
+                    # 优先使用已有的 polymarket_url，如果没有则根据 slug 或 market_id 构建
+                    polymarket_url = market_data.get('polymarket_url')
+                    if not polymarket_url:
+                        slug = market_data.get('slug')
+                        if slug and not str(slug).isdigit() and ('-' in str(slug) or any(c.isalpha() for c in str(slug))):
+                            # 使用有效的 slug
+                            polymarket_url = f"https://polymarket.com/event/{slug}"
+                        else:
+                            # 使用 markets 端点（更可靠）
+                            polymarket_url = f"https://polymarket.com/markets/{market_id}"
+                    
                     result.append({
                         "market_id": market_id,
                         "question": market_data.get('question', ''),
@@ -1249,7 +1261,7 @@ class MarketDataCollector:
                         "volume_24h": market_data.get('volume_24h', 0),
                         "liquidity": market_data.get('liquidity', 0),
                         "category": market_data.get('category', 'other'),
-                        "polymarket_url": market_data.get('polymarket_url', f"https://polymarket.com/event/{market_id}")
+                        "polymarket_url": polymarket_url
                     })
             
             logger.info(f"Total {len(result)} unique Polymarket events found for {symbol}")