diff --git a/internal/datacoord/index_builder.go b/internal/datacoord/index_builder.go
index c2561a3d32..97aae40a01 100644
--- a/internal/datacoord/index_builder.go
+++ b/internal/datacoord/index_builder.go
@@ -302,7 +302,7 @@ func (ib *indexBuilder) process(buildID UniqueID) bool {
 		}
 		if isDiskANNIndex(getIndexType(indexParams)) {
 			var err error
-			indexParams, err = indexparams.AppendDiskIndexBuildParams(Params, indexParams)
+			indexParams, err = indexparams.UpdateDiskIndexBuildParams(Params, indexParams)
 			if err != nil {
 				log.Ctx(ib.ctx).Warn("failed to append index build params", zap.Int64("buildID", buildID),
 					zap.Int64("nodeID", nodeID), zap.Error(err))
diff --git a/pkg/util/indexparams/index_params.go b/pkg/util/indexparams/index_params.go
index a07d67b669..ecdcd185ba 100644
--- a/pkg/util/indexparams/index_params.go
+++ b/pkg/util/indexparams/index_params.go
@@ -154,11 +154,11 @@ func NewBigDataExtraParamsFromMap(value map[string]string) (*BigDataIndexExtraPa
 // FillDiskIndexParams fill ratio params to index param on proxy node
 // Which will be used to calculate build and load params
 func FillDiskIndexParams(params *paramtable.ComponentParam, indexParams map[string]string) error {
-	maxDegree := params.CommonCfg.MaxDegree.GetValue()
-	searchListSize := params.CommonCfg.SearchListSize.GetValue()
-	pqCodeBudgetGBRatio := params.CommonCfg.PQCodeBudgetGBRatio.GetValue()
-	buildNumThreadsRatio := params.CommonCfg.BuildNumThreadsRatio.GetValue()
-	searchCacheBudgetGBRatio := params.CommonCfg.SearchCacheBudgetGBRatio.GetValue()
+	var maxDegree string
+	var searchListSize string
+	var pqCodeBudgetGBRatio string
+	var buildNumThreadsRatio string
+	var searchCacheBudgetGBRatio string
 
 	if params.AutoIndexConfig.Enable.GetAsBool() {
 		indexParams := params.AutoIndexConfig.IndexParams.GetAsJSONMap()
@@ -177,6 +177,13 @@ func FillDiskIndexParams(params *paramtable.ComponentParam, indexParams map[stri
 		}
 		pqCodeBudgetGBRatio = fmt.Sprintf("%f", extraParams.PQCodeBudgetGBRatio)
 		buildNumThreadsRatio = fmt.Sprintf("%f", extraParams.BuildNumThreadsRatio)
+		searchCacheBudgetGBRatio = fmt.Sprintf("%f", extraParams.SearchCacheBudgetGBRatio)
+	} else {
+		maxDegree = params.CommonCfg.MaxDegree.GetValue()
+		searchListSize = params.CommonCfg.SearchListSize.GetValue()
+		pqCodeBudgetGBRatio = params.CommonCfg.PQCodeBudgetGBRatio.GetValue()
+		buildNumThreadsRatio = params.CommonCfg.BuildNumThreadsRatio.GetValue()
+		searchCacheBudgetGBRatio = params.CommonCfg.SearchCacheBudgetGBRatio.GetValue()
 	}
 
 	indexParams[MaxDegreeKey] = maxDegree
@@ -197,12 +204,9 @@ func GetIndexParams(indexParams []*commonpb.KeyValuePair, key string) string {
 	return ""
 }
 
-// AppendDiskIndexBuildParams append index params for `buildIndex` (params not exist in `CreateIndex`)
-func AppendDiskIndexBuildParams(params *paramtable.ComponentParam, indexParams []*commonpb.KeyValuePair) ([]*commonpb.KeyValuePair, error) {
+// UpdateDiskIndexBuildParams update index params for `buildIndex` (override search cache size in `CreateIndex`)
+func UpdateDiskIndexBuildParams(params *paramtable.ComponentParam, indexParams []*commonpb.KeyValuePair) ([]*commonpb.KeyValuePair, error) {
 	existedVal := GetIndexParams(indexParams, SearchCacheBudgetRatioKey)
-	if len(existedVal) > 0 {
-		return indexParams, nil
-	}
 
 	var searchCacheBudgetGBRatio string
 	if params.AutoIndexConfig.Enable.GetAsBool() {
@@ -219,14 +223,33 @@ func AppendDiskIndexBuildParams(params *paramtable.ComponentParam, indexParams [
 		searchCacheBudgetGBRatio = fmt.Sprintf("%f", paramVal)
 	}
 
-	if len(searchCacheBudgetGBRatio) > 0 {
+	// append when not exist
+	if len(existedVal) == 0 {
 		indexParams = append(indexParams,
 			&commonpb.KeyValuePair{
 				Key:   SearchCacheBudgetRatioKey,
 				Value: searchCacheBudgetGBRatio,
 			})
+		return indexParams, nil
 	}
-	return indexParams, nil
+	// override when exist
+	updatedParams := make([]*commonpb.KeyValuePair, 0, len(indexParams))
+	for _, param := range indexParams {
+		if param.Key == SearchCacheBudgetRatioKey {
+			updatedParams = append(updatedParams,
+				&commonpb.KeyValuePair{
+					Key:   SearchCacheBudgetRatioKey,
+					Value: searchCacheBudgetGBRatio,
+				})
+		} else {
+			updatedParams = append(updatedParams,
+				&commonpb.KeyValuePair{
+					Key:   param.Key,
+					Value: param.Value,
+				})
+		}
+	}
+	return updatedParams, nil
 }
 
 // SetDiskIndexBuildParams set index build params with ratio params on indexNode
diff --git a/pkg/util/indexparams/index_params_test.go b/pkg/util/indexparams/index_params_test.go
index ac85303ceb..9b9030ff30 100644
--- a/pkg/util/indexparams/index_params_test.go
+++ b/pkg/util/indexparams/index_params_test.go
@@ -149,7 +149,7 @@ func TestDiskIndexParams(t *testing.T) {
 				Value: "4.0",
 			})
 
-		indexParams, err := AppendDiskIndexBuildParams(&params, indexParams)
+		indexParams, err := UpdateDiskIndexBuildParams(&params, indexParams)
 		assert.NoError(t, err)
 		assert.True(t, len(indexParams) == 4)
 
@@ -191,7 +191,7 @@ func TestDiskIndexParams(t *testing.T) {
 				Value: "4.0",
 			})
 
-		autoParams, err = AppendDiskIndexBuildParams(&params, autoParams)
+		autoParams, err = UpdateDiskIndexBuildParams(&params, autoParams)
 		assert.NoError(t, err)
 		assert.True(t, len(autoParams) == 4)
 
@@ -208,7 +208,7 @@ func TestDiskIndexParams(t *testing.T) {
 				}
 			`
 		params.Save(params.AutoIndexConfig.ExtraParams.Key, newJSONStr)
-		autoParams, err = AppendDiskIndexBuildParams(&params, autoParams)
+		autoParams, err = UpdateDiskIndexBuildParams(&params, autoParams)
 
 		assert.NoError(t, err)
 		assert.True(t, len(autoParams) == 4)
@@ -216,7 +216,7 @@ func TestDiskIndexParams(t *testing.T) {
 		val = GetIndexParams(autoParams, SearchCacheBudgetRatioKey)
 		iVal, iErr = strconv.ParseFloat(val, 64)
 		assert.NoError(t, iErr)
-		assert.Equal(t, 0.225, iVal)
+		assert.Equal(t, 0.325, iVal)
 	})
 
 	t.Run("set disk index build params", func(t *testing.T) {