declare global {

// 你的全局类型

} 

import { PageConfig } from "@tarojs/taro";

declare global {
    interface QyPageConfig extends PageConfig {}
}

参考：

https://www.cnblogs.com/sefaultment/p/10244685.html

https://koharubiyori.gitee.io/2020/08/24/Typescript/%E5%9C%A8TypeScript%E7%9A%84%E5%85%A8%E5%B1%80%E7%B1%BB%E5%9E%8B%E4%B8%AD%E4%BD%BF%E7%94%A8%E6%A8%A1%E5%9D%97%E5%AF%BC%E5%87%BA%E7%9A%84%E7%B1%BB%E5%9E%8B/