diff --git a/ccdi-project/src/main/java/com/ruoyi/ccdi/project/service/impl/CcdiModelParamServiceImpl.java b/ccdi-project/src/main/java/com/ruoyi/ccdi/project/service/impl/CcdiModelParamServiceImpl.java
index 67a3897..6c2b865 100644
--- a/ccdi-project/src/main/java/com/ruoyi/ccdi/project/service/impl/CcdiModelParamServiceImpl.java
+++ b/ccdi-project/src/main/java/com/ruoyi/ccdi/project/service/impl/CcdiModelParamServiceImpl.java
@@ -105,51 +105,65 @@ public class CcdiModelParamServiceImpl implements ICcdiModelParamService {
     @Override
     @Transactional(rollbackFor = Exception.class)
     public void saveParams(ModelParamSaveDTO saveDTO) {
-        Long projectId = saveDTO.getProjectId();
-        if (projectId == null) {
-            projectId = 0L;
-        }
-
-        // 空列表校验
-        if (saveDTO.getParams() == null || saveDTO.getParams().isEmpty()) {
-            throw new ServiceException("参数列表不能为空");
-        }
-
-        String username = SecurityUtils.getUsername();
-        Date now = new Date();
-
-        // 查询现有参数
-        List<CcdiModelParam> existingParams = modelParamMapper.selectByProjectAndModel(
-            projectId,
-            saveDTO.getModelCode()
-        );
-
-        if (existingParams.isEmpty()) {
-            throw new ServiceException("未找到模型参数配置");
-        }
-
-        // 构建Map提升性能
-        Map<String, CcdiModelParam> existingMap = existingParams.stream()
-            .collect(Collectors.toMap(CcdiModelParam::getParamCode, p -> p));
-
-        // 准备更新列表 - 只更新 param_value 字段
-        List<CcdiModelParam> updateList = new ArrayList<>();
-        for (ModelParamSaveDTO.ParamValueItem item : saveDTO.getParams()) {
-            CcdiModelParam existing = existingMap.get(item.getParamCode());
-
-            if (existing != null) {
-                // ⚠️ 关键:只修改 param_value 字段
-                CcdiModelParam updateParam = new CcdiModelParam();
-                updateParam.setId(existing.getId());
-                updateParam.setParamValue(item.getParamValue()); // 只更新阈值
-                updateParam.setUpdateBy(username);
-                updateParam.setUpdateTime(now);
-                updateList.add(updateParam);
+        try {
+            // 1. 参数验证
+            if (saveDTO.getProjectId() == null) {
+                throw new ServiceException("项目ID不能为空");
+            }
+            if (StringUtils.isBlank(saveDTO.getModelCode())) {
+                throw new ServiceException("模型编码不能为空");
+            }
+            if (saveDTO.getParams() == null || saveDTO.getParams().isEmpty()) {
+                throw new ServiceException("参数列表不能为空");
             }
-        }
 
-        if (!updateList.isEmpty()) {
-            modelParamMapper.batchUpdateParamValues(updateList);
+            Long projectId = saveDTO.getProjectId();
+
+            // 2. 如果是项目保存（projectId > 0），需要检查是否首次保存
+            if (projectId > 0) {
+                // 查询项目信息
+                CcdiProject project = projectMapper.selectById(projectId);
+                if (project == null) {
+                    throw new ServiceException("项目不存在");
+                }
+
+                // 3. 如果是首次保存（configType=default），需要复制系统默认参数
+                if ("default".equals(project.getConfigType())) {
+                    int copiedCount = copyDefaultParamsToProject(projectId, saveDTO.getModelCode());
+                    if (copiedCount == 0) {
+                        log.warn("系统默认参数为空，projectId={}, modelCode={}",
+                            projectId, saveDTO.getModelCode());
+                    }
+
+                    // 更新项目配置类型为 custom
+                    project.setConfigType("custom");
+                    projectMapper.updateById(project);
+
+                    log.info("项目配置类型已更新为 custom，projectId={}", projectId);
+                }
+            }
+
+            // 4. 更新参数值
+            String username = SecurityUtils.getUsername();
+            for (ModelParamSaveDTO.ParamValueItem item : saveDTO.getParams()) {
+                int updated = modelParamMapper.updateParamValue(
+                    projectId,
+                    saveDTO.getModelCode(),
+                    item.getParamCode(),
+                    item.getParamValue()
+                );
+                if (updated == 0) {
+                    log.warn("参数不存在或未更新，paramCode={}", item.getParamCode());
+                }
+            }
+
+        } catch (ServiceException e) {
+            // 业务异常，直接抛出
+            throw e;
+        } catch (Exception e) {
+            // 系统异常，记录日志并抛出
+            log.error("保存模型参数失败", e);
+            throw new ServiceException("保存模型参数失败：" + e.getMessage());
         }
     }