diff --git a/Dockerfile b/Dockerfile
index 2418323..69ba396 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -11,11 +11,11 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     wget \
     && rm -rf /var/lib/apt/lists/*
 
-# 安装 ONNX Runtime
-RUN wget -q https://github.com/microsoft/onnxruntime/releases/download/v1.16.3/onnxruntime-linux-x64-1.16.3.tgz \
-    && tar -xzf onnxruntime-linux-x64-1.16.3.tgz \
-    && mv onnxruntime-linux-x64-1.16.3 /usr/local/onnxruntime \
-    && rm onnxruntime-linux-x64-1.16.3.tgz
+# 安装 ONNX Runtime 1.18.0 (支持 IR version 10)
+RUN wget -q https://github.com/microsoft/onnxruntime/releases/download/v1.18.0/onnxruntime-linux-x64-1.18.0.tgz \
+    && tar -xzf onnxruntime-linux-x64-1.18.0.tgz \
+    && mv onnxruntime-linux-x64-1.18.0 /usr/local/onnxruntime \
+    && rm onnxruntime-linux-x64-1.18.0.tgz
 
 ENV ONNXRUNTIME_DIR=/usr/local/onnxruntime
 ENV PKG_CONFIG_PATH=/usr/lib/x86_64-linux-gnu/pkgconfig
diff --git a/internal/captcha/handler.go b/internal/captcha/handler.go
index b829172..fe08b05 100644
--- a/internal/captcha/handler.go
+++ b/internal/captcha/handler.go
@@ -25,15 +25,18 @@ type Handler struct {
 	mu        sync.RWMutex
 }
 
-// 模型配置：本地文件名 -> 远程文件名
-var modelConfigs = map[string]string{
-	"CRNN_Math.onnx":         "[AntiCAP]-CRNN_Math.onnx",
-	"OCR.onnx":               "[Dddd]-OCR.onnx",
-	"Rotation-RotNetR.onnx":  "[AntiCAP]-Rotation-RotNetR.onnx",
-	"Siamese-ResNet18.onnx":  "[AntiCAP]-Siamese-ResNet18.onnx",
-	"CharSets.txt":           "[Dddd]-CharSets.txt",
-	"Detection_Icon.onnx":    "Detection_Icon.onnx",
-	"Detection_Text.onnx":    "Detection_Text.onnx",
+// 模型配置：本地文件名 -> 远程文件名（可选模型用 optional 标记）
+var modelConfigs = map[string]struct {
+	remote   string
+	optional bool
+}{
+	"CRNN_Math.onnx":         {remote: "[AntiCAP]-CRNN_Math.onnx", optional: false},
+	"OCR.onnx":               {remote: "[Dddd]-OCR.onnx", optional: false},
+	"Rotation-RotNetR.onnx":  {remote: "[AntiCAP]-Rotation-RotNetR.onnx", optional: false},
+	"Siamese-ResNet18.onnx":  {remote: "[AntiCAP]-Siamese-ResNet18.onnx", optional: false},
+	"CharSets.txt":           {remote: "[Dddd]-CharSets.txt", optional: false},
+	"Detection_Icon.onnx":    {remote: "Detection_Icon.onnx", optional: true},
+	"Detection_Text.onnx":    {remote: "Detection_Text.onnx", optional: true},
 }
 
 // 从 Gitea 仓库下载（公开仓库，无需认证）
@@ -119,12 +122,16 @@ func (h *Handler) ensureModels() {
 		return
 	}
 
-	for localName, remoteName := range modelConfigs {
+	for localName, cfg := range modelConfigs {
 		localPath := filepath.Join(h.modelPath, localName)
 		if _, err := os.Stat(localPath); os.IsNotExist(err) {
-			fmt.Printf("下载模型: %s -> %s\n", remoteName, localName)
-			if err := h.downloadModel(remoteName, localPath); err != nil {
-				fmt.Printf("警告: 下载模型 %s 失败: %v\n", remoteName, err)
+			fmt.Printf("下载模型: %s -> %s\n", cfg.remote, localName)
+			if err := h.downloadModel(cfg.remote, localPath); err != nil {
+				if cfg.optional {
+					fmt.Printf("提示: 可选模型 %s 下载失败，相关功能不可用: %v\n", localName, err)
+				} else {
+					fmt.Printf("警告: 下载模型 %s 失败: %v\n", cfg.remote, err)
+				}
 			} else {
 				fmt.Printf("模型下载完成: %s\n", localName)
 			}