diff --git a/agent.go b/agent.go
index 24b434b..70682b2 100644
--- a/agent.go
+++ b/agent.go
@@ -3,18 +3,18 @@ package goba
 
 import (
 	"bytes"
-	"crypto/sha256"
-	"encoding/binary"
 	"encoding/json"
 	"fmt"
 	"image"
 	"io"
+	"math"
 	"net/http"
 	"strings"
 	"time"
 
 	"github.com/FloatTech/imgfactory"
 	"github.com/FloatTech/ttl"
+	"github.com/corona10/goimagehash"
 	"github.com/fumiama/deepinfra"
 	"github.com/fumiama/deepinfra/chat"
 	"github.com/fumiama/deepinfra/model"
@@ -121,19 +121,37 @@ func (ag *Agent) SetViewImageAPI(api deepinfra.API, p model.Protocol) {
 					logrus.Debugln("[goba] SetViewImageAPI read body err:", err)
 					continue
 				}
-				sum := sha256.Sum256(data)
-				k := binary.LittleEndian.Uint64(sum[:8])
-				if desc := ag.imgpcache.Get(k); desc != "" {
-					msgs[i].Data["__agent_desc__"] = desc
-					hasset = true
-					logrus.Debugln("[goba] SetViewImageAPI hit cache")
-					continue
-				}
 				img, _, err := image.Decode(bytes.NewReader(data))
 				if err != nil {
 					logrus.Debugln("[goba] SetViewImageAPI decode img err:", err)
 					continue
 				}
+				hsh, err := goimagehash.PerceptionHash(img)
+				if err != nil {
+					logrus.Debugln("[goba] SetViewImageAPI calc phash err:", err)
+					continue
+				}
+				d := math.MaxInt
+				desc := ""
+				_ = ag.imgpcache.Range(func(u uint64, s string) error {
+					ds, err := goimagehash.NewImageHash(u, goimagehash.PHash).Distance(hsh)
+					if err != nil {
+						logrus.Debugln("[goba] SetViewImageAPI calc phash distance err:", err)
+						return nil
+					}
+					if d > ds {
+						d = ds
+						desc = s
+					}
+					return nil
+				})
+				if d < 8 { // very similar (>87.5%)
+					msgs[i].Data["__agent_desc__"] = desc
+					hasset = true
+					logrus.Debugln("[goba] SetViewImageAPI hit cache with d:", d)
+					continue
+				}
+
 				img = imgfactory.Limit(img, 1024, 1024)
 				data, err = imgfactory.ToBytes(img)
 				if err != nil {
@@ -149,13 +167,13 @@ func (ag *Agent) SetViewImageAPI(api deepinfra.API, p model.Protocol) {
 					model.NewContentImageURL(imgs),
 					model.NewContentText("使用简洁清晰明确的一段中文纯文本描述图片"),
 				)
-				desc, err := api.Request(m)
+				desc, err = api.Request(m)
 				if err != nil {
 					logrus.Debugln("[goba] SetViewImageAPI request API err:", err)
 					continue
 				}
 				msgs[i].Data["__agent_desc__"] = desc
-				ag.imgpcache.Set(k, desc)
+				ag.imgpcache.Set(hsh.GetHash(), desc)
 				hasset = true
 			}
 			if hasset {
diff --git a/go.mod b/go.mod
index 900d605..55c400b 100644
--- a/go.mod
+++ b/go.mod
@@ -6,6 +6,7 @@ require (
 	github.com/FloatTech/imgfactory v0.2.2-0.20230413152719-e101cc3606ef
 	github.com/FloatTech/ttl v0.0.0-20240716161252-965925764562
 	github.com/RomiChan/syncx v0.0.0-20240418144900-b7402ffdebc7
+	github.com/corona10/goimagehash v1.1.1-0.20240121134706-d8115886f360
 	github.com/fumiama/deepinfra v0.0.0-20250924162107-cf156d49a0fa
 	github.com/pkg/errors v0.9.1
 	github.com/sirupsen/logrus v1.9.3
@@ -19,6 +20,7 @@ require (
 	github.com/ericpauley/go-quantize v0.0.0-20200331213906-ae555eb2afa4 // indirect
 	github.com/fumiama/imgsz v0.0.4 // indirect
 	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 // indirect
+	github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646 // indirect
 	github.com/tidwall/gjson v1.17.3 // indirect
 	github.com/tidwall/match v1.1.1 // indirect
 	github.com/tidwall/pretty v1.2.0 // indirect
diff --git a/go.sum b/go.sum
index 7306e29..0d65ead 100644
--- a/go.sum
+++ b/go.sum
@@ -6,6 +6,8 @@ github.com/FloatTech/ttl v0.0.0-20240716161252-965925764562 h1:snfw7FNFym1eNnLrQ
 github.com/FloatTech/ttl v0.0.0-20240716161252-965925764562/go.mod h1:fHZFWGquNXuHttu9dUYoKuNbm3dzLETnIOnm1muSfDs=
 github.com/RomiChan/syncx v0.0.0-20240418144900-b7402ffdebc7 h1:S/ferNiehVjNaBMNNBxUjLtVmP/YWD6Yh79RfPv4ehU=
 github.com/RomiChan/syncx v0.0.0-20240418144900-b7402ffdebc7/go.mod h1:vD7Ra3Q9onRtojoY5sMCLQ7JBgjUsrXDnDKyFxqpf9w=
+github.com/corona10/goimagehash v1.1.1-0.20240121134706-d8115886f360 h1:SvD9vQN+3r0wskoSrQ7IOyDmOtRIXhT3rlnf819r/bY=
+github.com/corona10/goimagehash v1.1.1-0.20240121134706-d8115886f360/go.mod h1:PFDP0Q0oYvEuipJHMSbeK8tjbuRzkQqjPDYm3n71ITA=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -19,6 +21,8 @@ github.com/fumiama/imgsz v0.0.4 h1:Lsasu2hdSSFS+vnD+nvR1UkiRMK7hcpyYCC0FzgSMFI=
 github.com/fumiama/imgsz v0.0.4/go.mod h1:bISOQVTlw9sRytPwe8ir7tAaEmyz9hSNj9n8mXMBG0E=
 github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 h1:DACJavvAHhabrF08vX0COfcOBJRhZ8lUbR+ZWIs0Y5g=
 github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0/go.mod h1:E/TSTwGwJL78qG/PmXZO1EjYhfJinVAhrmmHX6Z8B9k=
+github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646 h1:zYyBkD/k9seD2A7fsi6Oo2LfFZAehjjQMERAvZLEDnQ=
+github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646/go.mod h1:jpp1/29i3P1S/RLdc7JQKbRpFeM1dOBd8T9ki5s+AY8=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=