diff --git a/components/retriever/milvus2/search_mode/range.go b/components/retriever/milvus2/search_mode/range.go
index 0b005a2c9..aa76498f6 100644
--- a/components/retriever/milvus2/search_mode/range.go
+++ b/components/retriever/milvus2/search_mode/range.go
@@ -23,6 +23,7 @@ import (
 	"github.com/cloudwego/eino/components/retriever"
 	"github.com/cloudwego/eino/schema"
 	"github.com/milvus-io/milvus/client/v2/entity"
+	"github.com/milvus-io/milvus/client/v2/index"
 	"github.com/milvus-io/milvus/client/v2/milvusclient"
 
 	milvus2 "github.com/cloudwego/eino-ext/components/retriever/milvus2"
@@ -104,20 +105,22 @@ func (r *Range) BuildSearchOption(ctx context.Context, conf *milvus2.RetrieverCo
 		topK = *co.TopK
 	}
 
+	annParam := index.NewCustomAnnParam()
+	annParam.WithRadius(r.Radius)
+	if r.RangeFilter != nil {
+		annParam.WithRangeFilter(*r.RangeFilter)
+	}
+
 	searchOpt := milvusclient.NewSearchOption(conf.Collection, topK, []entity.Vector{entity.FloatVector(queryVector)}).
 		WithANNSField(conf.VectorField).
 		WithOutputFields(conf.OutputFields...).
-		WithSearchParam("radius", fmt.Sprintf("%v", r.Radius))
+		WithAnnParam(annParam)
 
 	// Apply metric type
 	if r.MetricType != "" {
 		searchOpt.WithSearchParam("metric_type", string(r.MetricType))
 	}
 
-	if r.RangeFilter != nil {
-		searchOpt = searchOpt.WithSearchParam("range_filter", fmt.Sprintf("%v", *r.RangeFilter))
-	}
-
 	if len(conf.Partitions) > 0 {
 		searchOpt = searchOpt.WithPartitions(conf.Partitions...)
 	}
diff --git a/components/retriever/milvus2/search_mode/range_test.go b/components/retriever/milvus2/search_mode/range_test.go
index 6e32212bb..a8bf3a881 100644
--- a/components/retriever/milvus2/search_mode/range_test.go
+++ b/components/retriever/milvus2/search_mode/range_test.go
@@ -18,6 +18,7 @@ package search_mode
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"testing"
 
@@ -25,6 +26,7 @@ import (
 	"github.com/cloudwego/eino/components/embedding"
 	"github.com/cloudwego/eino/components/retriever"
 	"github.com/cloudwego/eino/schema"
+	"github.com/milvus-io/milvus/client/v2/entity"
 	"github.com/milvus-io/milvus/client/v2/milvusclient"
 	"github.com/smartystreets/goconvey/convey"
 
@@ -79,17 +81,45 @@ func TestRange_BuildSearchOption(t *testing.T) {
 		}
 
 		convey.Convey("test basic range search option", func() {
-			r := NewRange(milvus2.L2, 1.0)
+			r := NewRange(milvus2.COSINE, 0.4)
 			opt, err := r.BuildSearchOption(ctx, config, queryVector)
 			convey.So(err, convey.ShouldBeNil)
-			convey.So(opt, convey.ShouldNotBeNil)
+
+			request, err := opt.Request()
+			convey.So(err, convey.ShouldBeNil)
+
+			searchParams := entity.KvPairsMap(request.GetSearchParams())
+			annParams := map[string]float64{}
+			err = json.Unmarshal([]byte(searchParams["params"]), &annParams)
+			convey.So(err, convey.ShouldBeNil)
+			convey.So(annParams, convey.ShouldResemble, map[string]float64{
+				"radius": 0.4,
+			})
+			convey.So(searchParams["metric_type"], convey.ShouldEqual, string(milvus2.COSINE))
+			_, hasRadius := searchParams["radius"]
+			convey.So(hasRadius, convey.ShouldBeFalse)
 		})
 
 		convey.Convey("test with range filter (ring search)", func() {
-			r := NewRange(milvus2.L2, 1.0).WithRangeFilter(0.5)
+			r := NewRange(milvus2.COSINE, 0.4).WithRangeFilter(1.0)
 			opt, err := r.BuildSearchOption(ctx, config, queryVector)
 			convey.So(err, convey.ShouldBeNil)
-			convey.So(opt, convey.ShouldNotBeNil)
+
+			request, err := opt.Request()
+			convey.So(err, convey.ShouldBeNil)
+
+			searchParams := entity.KvPairsMap(request.GetSearchParams())
+			annParams := map[string]float64{}
+			err = json.Unmarshal([]byte(searchParams["params"]), &annParams)
+			convey.So(err, convey.ShouldBeNil)
+			convey.So(annParams, convey.ShouldResemble, map[string]float64{
+				"radius":       0.4,
+				"range_filter": 1.0,
+			})
+			_, hasRadius := searchParams["radius"]
+			convey.So(hasRadius, convey.ShouldBeFalse)
+			_, hasRangeFilter := searchParams["range_filter"]
+			convey.So(hasRangeFilter, convey.ShouldBeFalse)
 		})
 
 		convey.Convey("test with partitions", func() {