diff --git a/server/src/assessment/services/question-bank.service.ts b/server/src/assessment/services/question-bank.service.ts
index a867f9f..2e72e94 100644
--- a/server/src/assessment/services/question-bank.service.ts
+++ b/server/src/assessment/services/question-bank.service.ts
@@ -2,6 +2,7 @@ import {
   Injectable,
   NotFoundException,
   ForbiddenException,
+  BadRequestException,
   Logger,
 } from '@nestjs/common';
 import { InjectRepository } from '@nestjs/typeorm';
@@ -87,15 +88,20 @@ export class QuestionBankService {
     tenantId: string | null,
   ): Promise<QuestionBank> {
     if (!createDto.name || !createDto.name.trim()) {
-      throw new Error('Question bank name is required');
+      throw new BadRequestException('Question bank name is required');
     }
-    const bank = this.bankRepository.create({
-      ...createDto,
+    const bankData: any = {
+      name: createDto.name,
+      description: createDto.description || '',
       createdBy: userId,
       tenantId: tenantId || null,
       status: QuestionBankStatus.DRAFT,
-    });
-    return this.bankRepository.save(bank);
+    };
+    if (createDto.templateId) {
+      bankData.template = { id: createDto.templateId };
+    }
+    const bank = this.bankRepository.create(bankData as any);
+    return this.bankRepository.save(bank as unknown as QuestionBank);
   }
 
   async findAll(
@@ -211,7 +217,7 @@ export class QuestionBankService {
     createDto: CreateQuestionBankItemDto,
   ): Promise<QuestionBankItem> {
     if (!createDto.questionText || !createDto.questionText.trim()) {
-      throw new Error('Question text is required');
+      throw new BadRequestException('Question text is required');
     }
     await this.findOne(bankId);
     const item = this.itemRepository.create({
@@ -261,11 +267,11 @@ export class QuestionBankService {
     const bank = await this.findOne(bankId);
 
     if (count <= 0 || count > 50) {
-      throw new Error('生成数量必须在 1-50 之间');
+      throw new BadRequestException('生成数量必须在 1-50 之间');
     }
 
     if (!knowledgeBaseContent || knowledgeBaseContent.trim().length < 10) {
-      throw new Error('知识库内容太短，无法生成有效题目');
+      throw new BadRequestException('知识库内容太短，无法生成有效题目');
     }
 
     this.logger.log(`[generateQuestions] Starting AI generation for bank ${bankId}, count: ${count}`);
@@ -316,7 +322,7 @@ export class QuestionBankService {
       let parsedQuestions = safeParseJson<any>(response.content as string);
       if (!parsedQuestions) {
         this.logger.error('[generateQuestions] Failed to parse JSON from AI response');
-        throw new Error('Invalid JSON format from AI');
+        throw new BadRequestException('Invalid JSON format from AI');
       }
 
       if (!Array.isArray(parsedQuestions)) {
diff --git a/web/services/questionBankService.ts b/web/services/questionBankService.ts
index b659a7a..bc1e617 100644
--- a/web/services/questionBankService.ts
+++ b/web/services/questionBankService.ts
@@ -146,7 +146,12 @@ export const questionBankService = {
       headers: { 'Content-Type': 'application/json' },
       body: JSON.stringify({ count, knowledgeBaseContent }),
     });
-    if (!response.ok) throw new Error('Failed to generate questions');
+    if (!response.ok) {
+      const errBody = await response.text().catch(() => '');
+      let msg = 'Failed to generate questions';
+      try { const parsed = JSON.parse(errBody); if (parsed.message) msg = parsed.message; } catch {}
+      throw new Error(msg);
+    }
     return await response.json();
   },