您可能希望将require Package 在一个函数中，该函数执行一些运行时类型检查。require无论如何都会返回any。
如果img字段的类型是一个datauri，那么它就很简单，你可以把它表示为一个类型：

type Base64Image = `data:image/${'jpeg'|'png'|'gif'};base64,${string}`
const base64ImageDecoder = /^data:image\/(jpeg|png|gif);base64,/;

const requireImage = (path: string) => {
    const data = require(path);
    if(typeof data === 'string' && base64ImageDecoder.test(data)) {
        return data as Base64Image
    } else throw Error(`"${path}" doesn't point to a Base64Image`)
}

type Obj = {
    img: Base64Image
}

const obj1: Obj = {
    img: requireImage('./../img-path-here')
}

const obj2: Obj = {
    // @ts-expect-error: not Base64Image
    img: './../img-path-here'
}

如果它是一个路径，那么在运行时检查它是否有效的方式取决于您和您的偏执程度，也许您只想确保使用了require，那么您可以跳过检查，但基本上是相同的过程：

type ImagePath = string & { _tag: 'ImagePath' }
const isImagePath = (data: unknown) => /* you do you */;

const requireImagePath = (path: string) => {
    const data = require(path);
    if(isImagePath(data)) {
        return data as ImagePath
    } else throw Error(`"${path}" doesn't point to an ImagePath`)
}

type Obj = {
    img: ImagePath
}

const obj1: Obj = {
    img: requireImagePath('./../img-path-here')
}

const obj2: Obj = {
    // @ts-expect-error: not ImagePath
    img: './../img-path-here'
}