diff --git a/frontend/src/lib/xray/vless-encryption.ts b/frontend/src/lib/xray/vless-encryption.ts
new file mode 100644
index 000000000..7c51daac7
--- /dev/null
+++ b/frontend/src/lib/xray/vless-encryption.ts
@@ -0,0 +1,29 @@
+export type VlessAuthKind =
+  | 'x25519'
+  | 'x25519_xorpub'
+  | 'x25519_random'
+  | 'mlkem768'
+  | 'mlkem768_xorpub'
+  | 'mlkem768_random';
+
+export const VLESS_AUTH_LABEL_KEYS: Record<VlessAuthKind, string> = {
+  x25519: 'pages.inbounds.vlessAuthX25519',
+  x25519_xorpub: 'pages.inbounds.vlessAuthX25519Xorpub',
+  x25519_random: 'pages.inbounds.vlessAuthX25519Random',
+  mlkem768: 'pages.inbounds.vlessAuthMlkem768',
+  mlkem768_xorpub: 'pages.inbounds.vlessAuthMlkem768Xorpub',
+  mlkem768_random: 'pages.inbounds.vlessAuthMlkem768Random',
+};
+
+const MLKEM768_MIN_KEY_LENGTH = 300;
+
+export function vlessEncryptionAuthKind(encryption: string): VlessAuthKind | null {
+  if (!encryption || encryption === 'none') return null;
+  const parts = encryption.split('.').filter(Boolean);
+  const authKey = parts[parts.length - 1] || '';
+  if (!authKey) return null;
+  const mode = parts[1] || 'native';
+  const keyType = authKey.length > MLKEM768_MIN_KEY_LENGTH ? 'mlkem768' : 'x25519';
+  if (mode === 'xorpub' || mode === 'random') return `${keyType}_${mode}`;
+  return keyType;
+}
diff --git a/frontend/src/pages/inbounds/form/InboundFormModal.tsx b/frontend/src/pages/inbounds/form/InboundFormModal.tsx
index 850029932..5e9130e74 100644
--- a/frontend/src/pages/inbounds/form/InboundFormModal.tsx
+++ b/frontend/src/pages/inbounds/form/InboundFormModal.tsx
@@ -41,6 +41,7 @@ import { Protocols } from '@/schemas/primitives';
 import { SockoptStreamSettingsSchema } from '@/schemas/protocols/stream/sockopt';
 import { HysteriaStreamSettingsSchema } from '@/schemas/protocols/stream/hysteria';
 import { createHysteriaTlsSettingsWithDefaultCert } from '@/lib/xray/inbound-tls-defaults';
+import { VLESS_AUTH_LABEL_KEYS, vlessEncryptionAuthKind } from '@/lib/xray/vless-encryption';
 import { SniffingSchema } from '@/schemas/primitives/sniffing';
 import { TcpStreamSettingsSchema } from '@/schemas/protocols/stream/tcp';
 import { KcpStreamSettingsSchema } from '@/schemas/protocols/stream/kcp';
@@ -317,27 +318,14 @@ export default function InboundFormModal({
     form.setFieldValue(['settings', 'encryption'], 'none');
   };
 
+  const vlessAuthKind = vlessEncryptionAuthKind(
+    typeof vlessEncryption === 'string' ? vlessEncryption : '',
+  );
   const selectedVlessAuth = (() => {
     const enc = typeof vlessEncryption === 'string' ? vlessEncryption : '';
     if (!enc || enc === 'none') return 'None';
-    const parts = enc.split('.').filter(Boolean);
-    const authKey = parts[parts.length - 1] || '';
-    if (!authKey) return t('pages.inbounds.vlessAuthCustom');
-    const mode = parts[1] || 'native';
-    const keyType = authKey.length > 300 ? 'mlkem768' : 'x25519';
-    if (mode === 'xorpub') {
-      return keyType === 'mlkem768'
-        ? t('pages.inbounds.vlessAuthMlkem768Xorpub')
-        : t('pages.inbounds.vlessAuthX25519Xorpub');
-    }
-    if (mode === 'random') {
-      return keyType === 'mlkem768'
-        ? t('pages.inbounds.vlessAuthMlkem768Random')
-        : t('pages.inbounds.vlessAuthX25519Random');
-    }
-    return keyType === 'mlkem768'
-      ? t('pages.inbounds.vlessAuthMlkem768')
-      : t('pages.inbounds.vlessAuthX25519');
+    if (!vlessAuthKind) return t('pages.inbounds.vlessAuthCustom');
+    return t(VLESS_AUTH_LABEL_KEYS[vlessAuthKind]);
   })();
 
   useEffect(() => {
@@ -703,7 +691,7 @@ export default function InboundFormModal({
 
       {protocol === Protocols.SHADOWSOCKS && <ShadowsocksFields form={form} isSSWith2022={isSSWith2022} />}
 
-      {protocol === Protocols.VLESS && <VlessFields saving={saving} selectedVlessAuth={selectedVlessAuth} network={network} security={security} getNewVlessEnc={getNewVlessEnc} clearVlessEnc={clearVlessEnc} />}
+      {protocol === Protocols.VLESS && <VlessFields saving={saving} selectedVlessAuth={selectedVlessAuth} vlessAuthKind={vlessAuthKind} network={network} security={security} getNewVlessEnc={getNewVlessEnc} clearVlessEnc={clearVlessEnc} />}
 
       {isFallbackHost && fallbacksCard}
       {(protocol === Protocols.VLESS || protocol === Protocols.TROJAN)
diff --git a/frontend/src/pages/inbounds/form/protocols/vless.tsx b/frontend/src/pages/inbounds/form/protocols/vless.tsx
index 310bc8ffe..85c029b34 100644
--- a/frontend/src/pages/inbounds/form/protocols/vless.tsx
+++ b/frontend/src/pages/inbounds/form/protocols/vless.tsx
@@ -1,18 +1,13 @@
-import { useState } from 'react';
+import { useEffect, useState } from 'react';
 import { useTranslation } from 'react-i18next';
 import { Button, Form, Input, InputNumber, Select, Space, Typography } from 'antd';
 
-type VlessAuthKind =
-  | 'x25519'
-  | 'x25519_xorpub'
-  | 'x25519_random'
-  | 'mlkem768'
-  | 'mlkem768_xorpub'
-  | 'mlkem768_random';
+import { VLESS_AUTH_LABEL_KEYS, type VlessAuthKind } from '@/lib/xray/vless-encryption';
 
 interface VlessFieldsProps {
   saving: boolean;
   selectedVlessAuth: string;
+  vlessAuthKind: VlessAuthKind | null;
   network: string;
   security: string;
   getNewVlessEnc: (kind: VlessAuthKind) => void;
@@ -22,22 +17,22 @@ interface VlessFieldsProps {
 export default function VlessFields({
   saving,
   selectedVlessAuth,
+  vlessAuthKind,
   network,
   security,
   getNewVlessEnc,
   clearVlessEnc,
 }: VlessFieldsProps) {
   const { t } = useTranslation();
-  const [authKind, setAuthKind] = useState<VlessAuthKind>('x25519');
+  const [authKind, setAuthKind] = useState<VlessAuthKind>(vlessAuthKind ?? 'x25519');
 
-  const authOptions = [
-    { value: 'x25519', label: t('pages.inbounds.vlessAuthX25519') },
-    { value: 'x25519_xorpub', label: t('pages.inbounds.vlessAuthX25519Xorpub') },
-    { value: 'x25519_random', label: t('pages.inbounds.vlessAuthX25519Random') },
-    { value: 'mlkem768', label: t('pages.inbounds.vlessAuthMlkem768') },
-    { value: 'mlkem768_xorpub', label: t('pages.inbounds.vlessAuthMlkem768Xorpub') },
-    { value: 'mlkem768_random', label: t('pages.inbounds.vlessAuthMlkem768Random') },
-  ];
+  useEffect(() => {
+    setAuthKind(vlessAuthKind ?? 'x25519');
+  }, [vlessAuthKind]);
+
+  const authOptions = (Object.entries(VLESS_AUTH_LABEL_KEYS) as [VlessAuthKind, string][]).map(
+    ([value, labelKey]) => ({ value, label: t(labelKey) }),
+  );
 
   return (
     <>
diff --git a/frontend/src/test/vless-encryption.test.ts b/frontend/src/test/vless-encryption.test.ts
new file mode 100644
index 000000000..be0052449
--- /dev/null
+++ b/frontend/src/test/vless-encryption.test.ts
@@ -0,0 +1,27 @@
+import { describe, it, expect } from 'vitest';
+
+import { vlessEncryptionAuthKind } from '@/lib/xray/vless-encryption';
+
+const x25519Key = 'kO9pIKKPtoUCzo3ZWfWfp0lQoWCyJC1TqL8oz1hpsFM';
+const mlkem768Key = 'A'.repeat(1590);
+
+describe('vlessEncryptionAuthKind', () => {
+  const cases: { name: string; encryption: string; want: ReturnType<typeof vlessEncryptionAuthKind> }[] = [
+    { name: 'empty string', encryption: '', want: null },
+    { name: 'none', encryption: 'none', want: null },
+    { name: 'only dots', encryption: '...', want: null },
+    { name: 'x25519 native', encryption: `mlkem768x25519plus.native.600s.${x25519Key}`, want: 'x25519' },
+    { name: 'x25519 xorpub', encryption: `mlkem768x25519plus.xorpub.600s.${x25519Key}`, want: 'x25519_xorpub' },
+    { name: 'x25519 random', encryption: `mlkem768x25519plus.random.600s.${x25519Key}`, want: 'x25519_random' },
+    { name: 'mlkem768 native', encryption: `mlkem768x25519plus.native.600s.${mlkem768Key}`, want: 'mlkem768' },
+    { name: 'mlkem768 xorpub', encryption: `mlkem768x25519plus.xorpub.600s.${mlkem768Key}`, want: 'mlkem768_xorpub' },
+    { name: 'mlkem768 random', encryption: `mlkem768x25519plus.random.600s.${mlkem768Key}`, want: 'mlkem768_random' },
+    { name: 'two-segment value treated as native', encryption: `mlkem768x25519plus.${x25519Key}`, want: 'x25519' },
+  ];
+
+  for (const c of cases) {
+    it(c.name, () => {
+      expect(vlessEncryptionAuthKind(c.encryption)).toBe(c.want);
+    });
+  }
+});