diff --git a/app/src/main/java/io/legado/app/data/entities/BookChapter.kt b/app/src/main/java/io/legado/app/data/entities/BookChapter.kt
index b88151e5d..8fa130d31 100644
--- a/app/src/main/java/io/legado/app/data/entities/BookChapter.kt
+++ b/app/src/main/java/io/legado/app/data/entities/BookChapter.kt
@@ -54,5 +54,8 @@ data class BookChapter(
         variable = GSON.toJson(variableMap)
     }
 
+    fun getVariableValue(book: Book, key: String): String? {
+        return variableMap?.get(key) ?: book.variableMap?.get(key)
+    }
 }