diff --git a/epublib/src/main/java/me/ag2s/epublib/util/StringUtil.java b/epublib/src/main/java/me/ag2s/epublib/util/StringUtil.java
index fa6757aaf..acb3093e9 100644
--- a/epublib/src/main/java/me/ag2s/epublib/util/StringUtil.java
+++ b/epublib/src/main/java/me/ag2s/epublib/util/StringUtil.java
@@ -282,6 +282,9 @@ public class StringUtil {
         if (m.find()) {
             s= m.group(1);
         }
+        if(s==null){
+            return "";
+        }
         //移除GBK中文全角空格
         s = s.replace("　", "");
         return s;