diff --git a/MdeModulePkg/Universal/Console/ConSplitterDxe/ConSplitter.c b/MdeModulePkg/Universal/Console/ConSplitterDxe/ConSplitter.c
index 2508273398..bcb9fd6f73 100644
--- a/MdeModulePkg/Universal/Console/ConSplitterDxe/ConSplitter.c
+++ b/MdeModulePkg/Universal/Console/ConSplitterDxe/ConSplitter.c
@@ -2109,6 +2109,8 @@ ConSplitterGrowMapTable (
   INT32 *OldTextOutModeMap;
   INT32 *SrcAddress;
   INT32 Index;
+  UINTN OldStepSize;
+  UINTN NewStepSize;
 
   NewSize           = Private->TextOutListCount * sizeof (INT32);
   OldTextOutModeMap = Private->TextOutModeMap;
@@ -2146,14 +2148,26 @@ ConSplitterGrowMapTable (
     Size        = Private->CurrentNumberOfConsoles * sizeof (INT32);
     Index       = 0;
     SrcAddress  = OldTextOutModeMap;
+    NewStepSize = NewSize / sizeof(INT32);    
+    // If Private->CurrentNumberOfConsoles is not zero and OldTextOutModeMap
+    // is not NULL, it indicates that the original TextOutModeMap is not enough
+    // for the new console devices and has been enlarged by CONSOLE_SPLITTER_ALLOC_UNIT columns.
+    //
+    OldStepSize = NewStepSize - CONSOLE_SPLITTER_ALLOC_UNIT;
 
     //
     // Copy the old data to the new one
     //
     while (Index < Private->TextOutMode.MaxMode) {
       CopyMem (TextOutModeMap, SrcAddress, Size);
-      TextOutModeMap += NewSize;
-      SrcAddress += Size;
+      //
+      // Go to next row of new TextOutModeMap.
+      //
+      TextOutModeMap += NewStepSize;
+      //
+      // Go to next row of old TextOutModeMap.
+      //
+      SrcAddress += OldStepSize;
       Index++;
     }
     //