diff --git a/internal/admin/handler_accounts_testing.go b/internal/admin/handler_accounts_testing.go
index 2a8a447..a05d6cf 100644
--- a/internal/admin/handler_accounts_testing.go
+++ b/internal/admin/handler_accounts_testing.go
@@ -157,7 +157,7 @@ func (h *Handler) testAccount(ctx context.Context, acc config.Account, model, me
 		result["message"] = "获取 PoW 失败: " + err.Error()
 		return result
 	}
-	payload := map[string]any{"chat_session_id": sessionID, "prompt": "<｜User｜>" + message, "ref_file_ids": []any{}, "thinking_enabled": thinking, "search_enabled": search}
+	payload := map[string]any{"chat_session_id": sessionID, "prompt": "<｜User｜>\n" + message, "ref_file_ids": []any{}, "thinking_enabled": thinking, "search_enabled": search}
 	resp, err := h.DS.CallCompletion(ctx, authCtx, payload, pow, 1)
 	if err != nil {
 		result["message"] = "请求失败: " + err.Error()
diff --git a/internal/prompt/messages.go b/internal/prompt/messages.go
index 80333de..daf5b84 100644
--- a/internal/prompt/messages.go
+++ b/internal/prompt/messages.go
@@ -32,30 +32,31 @@ func MessagesPrepare(messages []map[string]any) string {
 		merged = append(merged, msg)
 	}
 	parts := make([]string, 0, len(merged))
-	for i, m := range merged {
+	for _, m := range merged {
 		switch m.Role {
 		case "assistant":
-			parts = append(parts, "<｜Assistant｜>"+m.Text+"<｜end▁of▁sentence｜>")
+			// Keep assistant turns on their own block so the model sees a clear
+			// boundary between prior answer text and the EOS marker.
+			parts = append(parts, "<｜Assistant｜>\n"+m.Text+"\n<｜end▁of▁sentence｜>")
 		case "tool":
-			if i > 0 {
-				parts = append(parts, "<｜Tool｜>"+m.Text)
-			} else {
-				parts = append(parts, m.Text)
+			if strings.TrimSpace(m.Text) != "" {
+				parts = append(parts, "<｜Tool｜>\n"+m.Text)
 			}
 		case "system":
-			// Clear system boundary improves R1 and V3 context understanding significantly
-			if strings.TrimSpace(m.Text) != "" {
-				parts = append(parts, "<system_instructions>\n"+strings.TrimSpace(m.Text)+"\n</system_instructions>\n\n")
+			// Clear system boundary improves R1 and V3 context understanding significantly.
+			if text := strings.TrimSpace(m.Text); text != "" {
+				parts = append(parts, "<system_instructions>\n"+text+"\n</system_instructions>")
 			}
 		case "user":
-			// Always prepend <｜User｜> to user messages. DeepSeek R1 reasoning triggers best
-			// and aligns context perfectly when the user turn is explicitly marked.
-			parts = append(parts, "<｜User｜>"+m.Text)
+			// Put user turns on their own line so the role transition is explicit.
+			parts = append(parts, "<｜User｜>\n"+m.Text)
 		default:
-			parts = append(parts, m.Text)
+			if strings.TrimSpace(m.Text) != "" {
+				parts = append(parts, m.Text)
+			}
 		}
 	}
-	out := strings.Join(parts, "")
+	out := strings.Join(parts, "\n\n")
 	return markdownImagePattern.ReplaceAllString(out, `[${1}](${2})`)
 }
 
diff --git a/internal/util/messages_test.go b/internal/util/messages_test.go
index ab11b59..2ec3f50 100644
--- a/internal/util/messages_test.go
+++ b/internal/util/messages_test.go
@@ -12,7 +12,7 @@ func TestMessagesPrepareBasic(t *testing.T) {
 	if got == "" {
 		t.Fatal("expected non-empty prompt")
 	}
-	if got != "<｜User｜>Hello" {
+	if got != "<｜User｜>\nHello" {
 		t.Fatalf("unexpected prompt: %q", got)
 	}
 }
@@ -25,6 +25,15 @@ func TestMessagesPrepareRoles(t *testing.T) {
 		{"role": "user", "content": "How are you"},
 	}
 	got := MessagesPrepare(messages)
+	if !contains(got, "<system_instructions>\nYou are helper\n</system_instructions>\n\n<｜User｜>\nHi") {
+		t.Fatalf("expected system/user separation in %q", got)
+	}
+	if !contains(got, "<｜User｜>\nHi\n\n<｜Assistant｜>\nHello") {
+		t.Fatalf("expected user/assistant separation in %q", got)
+	}
+	if !contains(got, "<｜Assistant｜>\nHello\n<｜end▁of▁sentence｜>\n\n<｜User｜>\nHow are you") {
+		t.Fatalf("expected assistant/user separation in %q", got)
+	}
 	if !contains(got, "<｜Assistant｜>") {
 		t.Fatalf("expected assistant marker in %q", got)
 	}
@@ -55,7 +64,7 @@ func TestMessagesPrepareArrayTextVariants(t *testing.T) {
 		},
 	}
 	got := MessagesPrepare(messages)
-	if got != "<｜User｜>line1\nline2" {
+	if got != "<｜User｜>\nline1\nline2" {
 		t.Fatalf("unexpected content from text variants: %q", got)
 	}
 }