diff --git a/charts/kubezero-istio/templates/istio-private-ingress.yaml b/charts/kubezero-istio/templates/istio-private-ingress.yaml
index 83bbce0f..46c6519d 100644
--- a/charts/kubezero-istio/templates/istio-private-ingress.yaml
+++ b/charts/kubezero-istio/templates/istio-private-ingress.yaml
@@ -66,6 +66,7 @@ spec:
 
   meshConfig:
     accessLogFile: /dev/stdout
+    accessLogEncoding: json
 
   values:
     gateways:
diff --git a/charts/kubezero-istio/templates/istio.yaml b/charts/kubezero-istio/templates/istio.yaml
index 877ae430..6a0a48ef 100644
--- a/charts/kubezero-istio/templates/istio.yaml
+++ b/charts/kubezero-istio/templates/istio.yaml
@@ -89,6 +89,7 @@ spec:
       enabled: false
   meshConfig:
     accessLogFile: /dev/stdout
+    accessLogEncoding: json
   values:
     gateways:
       istio-ingressgateway: