diff --git a/src/main/java/run/halo/app/controller/admin/api/ThemeController.java b/src/main/java/run/halo/app/controller/admin/api/ThemeController.java
index 340551adc..04d57ff35 100644
--- a/src/main/java/run/halo/app/controller/admin/api/ThemeController.java
+++ b/src/main/java/run/halo/app/controller/admin/api/ThemeController.java
@@ -5,6 +5,7 @@ import org.springframework.http.HttpStatus;
 import org.springframework.web.bind.annotation.*;
 import org.springframework.web.multipart.MultipartFile;
 import run.halo.app.annotation.DisableOnCondition;
+import run.halo.app.cache.lock.CacheLock;
 import run.halo.app.handler.theme.config.support.Group;
 import run.halo.app.handler.theme.config.support.ThemeProperty;
 import run.halo.app.model.params.ThemeContentParam;
@@ -144,6 +145,7 @@ public class ThemeController {
 
     @PostMapping("{themeId}/settings")
     @ApiOperation("Saves theme settings")
+    @CacheLock(prefix = "save_theme_setting_by_themeId")
     public void saveSettingsBy(@PathVariable("themeId") String themeId,
             @RequestBody Map<String, Object> settings) {
         themeSettingService.save(settings, themeId);
diff --git a/src/main/java/run/halo/app/service/impl/ThemeSettingServiceImpl.java b/src/main/java/run/halo/app/service/impl/ThemeSettingServiceImpl.java
index 93fc0a295..33c909a0f 100644
--- a/src/main/java/run/halo/app/service/impl/ThemeSettingServiceImpl.java
+++ b/src/main/java/run/halo/app/service/impl/ThemeSettingServiceImpl.java
@@ -4,6 +4,7 @@ import freemarker.template.Configuration;
 import freemarker.template.TemplateModelException;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.commons.lang3.StringUtils;
+import org.springframework.data.domain.Example;
 import org.springframework.lang.NonNull;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
@@ -87,7 +88,10 @@ public class ThemeSettingServiceImpl extends AbstractCrudService<ThemeSetting, I
                     log.debug("Creating theme setting: [{}]", setting);
                     return setting;
                 });
-
+        // Determine whether the data already exists
+        if (themeSettingRepository.findOne(Example.of(themeSetting)).isPresent()) {
+            return null;
+        }
         // Save the theme setting
         return themeSettingRepository.save(themeSetting);
     }