diff --git a/api/core/rag/splitter/fixed_text_splitter.py b/api/core/rag/splitter/fixed_text_splitter.py
index 801d2a2a52..e95c009292 100644
--- a/api/core/rag/splitter/fixed_text_splitter.py
+++ b/api/core/rag/splitter/fixed_text_splitter.py
@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import codecs
 import re
 from typing import Any
 
@@ -52,7 +53,7 @@ class FixedRecursiveCharacterTextSplitter(EnhanceRecursiveCharacterTextSplitter)
     def __init__(self, fixed_separator: str = "\n\n", separators: list[str] | None = None, **kwargs: Any):
         """Create a new TextSplitter."""
         super().__init__(**kwargs)
-        self._fixed_separator = fixed_separator
+        self._fixed_separator = codecs.decode(fixed_separator, "unicode_escape")
         self._separators = separators or ["\n\n", "\n", "。", ". ", " ", ""]
 
     def split_text(self, text: str) -> list[str]:
diff --git a/api/tests/unit_tests/core/rag/splitter/test_text_splitter.py b/api/tests/unit_tests/core/rag/splitter/test_text_splitter.py
index 7d246ac3cc..943a9e5712 100644
--- a/api/tests/unit_tests/core/rag/splitter/test_text_splitter.py
+++ b/api/tests/unit_tests/core/rag/splitter/test_text_splitter.py
@@ -901,6 +901,13 @@ class TestFixedRecursiveCharacterTextSplitter:
         # Verify no empty chunks
         assert all(len(chunk) > 0 for chunk in result)
 
+    def test_double_slash_n(self):
+        data = "chunk 1\n\nsubchunk 1.\nsubchunk 2.\n\n---\n\nchunk 2\n\nsubchunk 1\nsubchunk 2."
+        separator = "\\n\\n---\\n\\n"
+        splitter = FixedRecursiveCharacterTextSplitter(fixed_separator=separator)
+        chunks = splitter.split_text(data)
+        assert chunks == ["chunk 1\n\nsubchunk 1.\nsubchunk 2.", "chunk 2\n\nsubchunk 1\nsubchunk 2."]
+
 
 # ============================================================================
 # Test Metadata Preservation