diff --git a/src/utils/modelConfigHelper.js b/src/utils/modelConfigHelper.js
new file mode 100644
index 0000000..41e8ec9
--- /dev/null
+++ b/src/utils/modelConfigHelper.js
@@ -0,0 +1,160 @@
+// 模型配置共享工具函数
+// 供 Painting / Video descriptor 使用
+
+/**
+ * 检测 dimension 配置模式
+ * @param {object | null} config - 模型配置对象
+ * @returns {object | null}
+ *   - combined: { type: 'combined', config: dimension子对象, paramName: string }
+ *   - split:    { type: 'split', wParam: 宽度参数, hParam: 高度参数 }
+ *   - null:     无 dimension 参数
+ */
+export function getDimConfig(config) {
+  if (!config) return null
+  const dimParam = config.params.find((p) => p.ui === 'dimension')
+  if (dimParam) return { type: 'combined', config: dimParam.dimension, paramName: dimParam.name }
+  const wParam = config.params.find((p) => p.ui === 'dimensionWidth')
+  const hParam = config.params.find((p) => p.ui === 'dimensionHeight')
+  if (wParam && hParam) return { type: 'split', wParam, hParam }
+  return null
+}
+
+/**
+ * 检查 showWhen 条件是否满足
+ * @param {object} param - 参数定义（可能含 showWhen）
+ * @param {object} paramValues - 当前所有参数值
+ * @returns {boolean}
+ */
+export function checkShowWhen(param, paramValues) {
+  if (!param.showWhen) return true
+  return Object.entries(param.showWhen).every(([key, expected]) => {
+    return paramValues[key] === expected
+  })
+}
+
+/**
+ * 将 API 返回的 config 同步到响应式 state
+ *
+ * state 对象需包含以下属性（均为 ref 或 reactive）：
+ *   modelConfig, paramValues, proportion, resolution, quantity, quality,
+ *   customWidth, customHight, dimWidth, dimHeight, promptPlaceholder
+ */
+export function syncDefaults(config, state) {
+  const {
+    modelConfig,
+    paramValues,
+    proportion,
+    resolution,
+    quantity,
+    quality,
+    customWidth,
+    customHight,
+    dimWidth,
+    dimHeight,
+    promptPlaceholder
+  } = state
+
+  modelConfig.value = config
+  if (!config) return
+
+  // 1. dimension.separator → 生成 parse/format（在遍历 params 之前完成）
+  config.params.forEach((p) => {
+    if (p.ui === 'dimension' && p.dimension?.separator && !p.dimension.parse) {
+      const sep = p.dimension.separator
+      p.dimension.parse = (val) => {
+        const parts = (val || '').split(sep)
+        return { width: Number.parseInt(parts[0]) || 0, height: Number.parseInt(parts[1]) || 0 }
+      }
+      p.dimension.format = (w, h) => `${w}${sep}${h}`
+    }
+  })
+
+  // 2. 初始化 paramValues（已存在的 key 保留，避免切换模型时丢失值）
+  config.params.forEach((p) => {
+    if (!(p.name in paramValues)) {
+      paramValues[p.name] = p.default ?? (p.name === 'outputFormat' ? 'png' : '')
+    }
+  })
+
+  // 3. 同步专用 ref
+  const ratioParam = config.params.find((p) => p.ui === 'proportion')
+  if (ratioParam) proportion.value = ratioParam.default || '1:1'
+
+  const resParam = config.params.find((p) => p.ui === 'resolution')
+  if (resParam) resolution.value = resParam.default || '2k'
+
+  const qtyParam = config.params.find((p) => p.ui === 'quantity')
+  if (qtyParam) quantity.value = qtyParam.default || 1
+
+  const cwParam = config.params.find((p) => p.name === 'customWidth')
+  if (cwParam) customWidth.value = cwParam.default || 1024
+
+  const chParam = config.params.find((p) => p.name === 'customHight')
+  if (chParam) customHight.value = chParam.default || 1024
+
+  const qualityParam = config.params.find((p) => p.name === 'quality')
+  if (qualityParam) quality.value = qualityParam.default || 'medium'
+
+  // 4. dimension 初始化
+  const dc = getDimConfig(config)
+  if (dc?.type === 'split') {
+    dimWidth.value = dc.wParam.default || 1024
+    dimHeight.value = dc.hParam.default || 1024
+  } else if (dc?.type === 'combined') {
+    const dimParam = config.params.find((p) => p.name === dc.paramName)
+    const raw = dimParam?.default || ''
+    const parsed = dc.config.parse(raw)
+    dimWidth.value = parsed.width
+    dimHeight.value = parsed.height
+  }
+
+  // 5. promptPlaceholder 同步
+  if (config.promptPlaceholder) {
+    promptPlaceholder.value = config.promptPlaceholder
+  }
+}
+
+/**
+ * 将专用 ref 的当前值回写到 paramValues
+ * （在 buildTaskBody 之前调用）
+ */
+export function syncParamValues(config, state) {
+  const {
+    paramValues,
+    proportion,
+    resolution,
+    quantity,
+    customWidth,
+    customHight,
+    dimWidth,
+    dimHeight,
+    quality
+  } = state
+
+  const ratioParam = config?.params?.find((p) => p.ui === 'proportion')
+  if (ratioParam) paramValues[ratioParam.name] = proportion.value
+
+  const resParam = config?.params?.find((p) => p.ui === 'resolution')
+  if (resParam) paramValues[resParam.name] = resolution.value
+
+  const qtyParam = config?.params?.find((p) => p.ui === 'quantity')
+  if (qtyParam) paramValues[qtyParam.name] = quantity.value
+
+  if (config?.params?.find((p) => p.name === 'customWidth')) {
+    paramValues.customWidth = customWidth.value
+  }
+  if (config?.params?.find((p) => p.name === 'customHight')) {
+    paramValues.customHight = customHight.value
+  }
+  if (config?.params?.find((p) => p.name === 'quality')) {
+    paramValues.quality = quality.value
+  }
+
+  const dc = getDimConfig(config)
+  if (dc?.type === 'split') {
+    paramValues[dc.wParam.name] = dimWidth.value
+    paramValues[dc.hParam.name] = dimHeight.value
+  } else if (dc?.type === 'combined') {
+    paramValues[dc.paramName] = dc.config.format(dimWidth.value, dimHeight.value)
+  }
+}