diff --git a/scripts/dev-api.js b/scripts/dev-api.js
index 4020083..f59f6e1 100644
--- a/scripts/dev-api.js
+++ b/scripts/dev-api.js
@@ -6313,6 +6313,7 @@ export function buildHermesChannelConfigValues(config = {}, envValues = {}) {
       putHermesString(form, extra, 'app_token')
       form.appToken = hermesEnvValue(envValues, 'SLACK_APP_TOKEN') || form.appToken || ''
       putHermesString(form, extra, 'signing_secret')
+      form.signingSecret = hermesEnvValue(envValues, 'SLACK_SIGNING_SECRET') || form.signingSecret || ''
       putHermesString(form, extra, 'webhook_path')
     } else if (platform === 'feishu') {
       for (const key of ['app_id', 'app_secret', 'domain', 'connection_mode', 'webhook_path', 'reaction_notifications']) {
@@ -6772,6 +6773,7 @@ export function buildHermesChannelEnvUpdates(platform, form = {}) {
   } else if (platform === 'slack') {
     updates.SLACK_BOT_TOKEN = String(form.botToken || '').trim()
     updates.SLACK_APP_TOKEN = String(form.appToken || '').trim()
+    updates.SLACK_SIGNING_SECRET = String(form.signingSecret || '').trim()
     updates.SLACK_ALLOWED_USERS = csvEnvValue(form.allowFrom)
     if (Object.hasOwn(form, 'requireMention')) updates.SLACK_REQUIRE_MENTION = boolEnvValue(form.requireMention)
   } else if (platform === 'feishu') {
diff --git a/src-tauri/src/commands/hermes.rs b/src-tauri/src/commands/hermes.rs
index 8d5da33..5d0b783 100644
--- a/src-tauri/src/commands/hermes.rs
+++ b/src-tauri/src/commands/hermes.rs
@@ -3402,6 +3402,13 @@ fn build_hermes_channel_config_values(
                     .unwrap_or_default();
                 form.insert("appToken".to_string(), Value::String(app_token));
                 insert_json_string_if_present(&mut form, &extra, "signing_secret", "signingSecret");
+                let signing_secret = hermes_env_value(env_values, "SLACK_SIGNING_SECRET")
+                    .or_else(|| json_form_string(&form, "signingSecret"))
+                    .unwrap_or_default();
+                form.insert(
+                    "signingSecret".to_string(),
+                    Value::String(signing_secret),
+                );
                 insert_json_string_if_present(&mut form, &extra, "webhook_path", "webhookPath");
             }
             "feishu" => {
@@ -11182,6 +11189,10 @@ fn build_hermes_channel_env_updates(platform: &str, form: &Value) -> Vec<(String
                 "SLACK_APP_TOKEN",
                 form_string(form, "appToken").unwrap_or_default(),
             );
+            push(
+                "SLACK_SIGNING_SECRET",
+                form_string(form, "signingSecret").unwrap_or_default(),
+            );
             push("SLACK_ALLOWED_USERS", csv_env_value(form, "allowFrom"));
             if let Some(value) = form_bool(form, "requireMention") {
                 push("SLACK_REQUIRE_MENTION", bool_env_value(value));
@@ -11431,6 +11442,7 @@ fn write_hermes_channel_env(platform: &str, form: &Value) -> Result<(), String>
         "slack" => vec![
             "SLACK_BOT_TOKEN",
             "SLACK_APP_TOKEN",
+            "SLACK_SIGNING_SECRET",
             "SLACK_ALLOWED_USERS",
             "SLACK_REQUIRE_MENTION",
         ],
@@ -24515,6 +24527,21 @@ platforms:
             config["platforms"]["slack"]["extra"]["unknown_option"].as_str(),
             Some("keep-me")
         );
+
+        let env = build_hermes_channel_env_updates(
+            "slack",
+            &json!({
+                "enabled": true,
+                "botToken": "xoxb-new",
+                "appToken": "xapp-new",
+                "signingSecret": "new-signing-secret",
+                "webhookPath": "/slack/events",
+            }),
+        );
+        assert!(env.contains(&(
+            "SLACK_SIGNING_SECRET".to_string(),
+            "new-signing-secret".to_string()
+        )));
     }
 
     #[test]
diff --git a/tests/hermes-channel-config.test.js b/tests/hermes-channel-config.test.js
index 7ff5419..7b18dda 100644
--- a/tests/hermes-channel-config.test.js
+++ b/tests/hermes-channel-config.test.js
@@ -358,6 +358,38 @@ test('Hermes 渠道保存会从 YAML 清理旧凭证，避免覆盖 .env 运行
   assert.equal(next.platforms.slack.extra.signing_secret, undefined)
   assert.equal(next.platforms.slack.extra.webhook_path, '/slack/events')
   assert.equal(next.platforms.slack.extra.unknown_option, 'keep-me')
+
+  const env = buildHermesChannelEnvUpdates('slack', {
+    enabled: true,
+    botToken: 'xoxb-new',
+    appToken: 'xapp-new',
+    signingSecret: 'new-signing-secret',
+    webhookPath: '/slack/events',
+  })
+  assert.equal(env.SLACK_BOT_TOKEN, 'xoxb-new')
+  assert.equal(env.SLACK_APP_TOKEN, 'xapp-new')
+  assert.equal(env.SLACK_SIGNING_SECRET, 'new-signing-secret')
+})
+
+test('Hermes Slack 读取会从 .env 回填 signing secret', () => {
+  const values = buildHermesChannelConfigValues({
+    platforms: {
+      slack: {
+        enabled: true,
+        extra: {
+          webhook_path: '/slack/events',
+        },
+      },
+    },
+  }, {
+    SLACK_SIGNING_SECRET: 'env-signing-secret',
+    SLACK_BOT_TOKEN: 'xoxb-env',
+    SLACK_APP_TOKEN: 'xapp-env',
+  })
+
+  assert.equal(values.slack.signingSecret, 'env-signing-secret')
+  assert.equal(values.slack.botToken, 'xoxb-env')
+  assert.equal(values.slack.appToken, 'xapp-env')
 })
 
 test('Hermes 钉钉保存会使用运行时实际读取的字段', () => {