how to solve it?

you can upload the background image to the server first, and then use the absolute address in vue, that is, the URL of the image resource, so that it will not be invalidated.

small images are considered to be directly transferred to base64 to be packaged into the code. If you have a big picture, take a look at the configuration.

add.

I don't know if the landlord has solved it.

look at the official documentation, it seems that you want to overwrite (uncertain) in vue.config.js

I used a silly method to copy the img folder directly into css

  chainWebpack: config => {
    config.resolve.alias
      .set('assets', resolve('src/assets'))
      .set('@', resolve('src'))
    config.output.filename('[name].js?[hash]').end()
  }
// .vue
background: url('~assets/images/right-glay.png')

~ will parse assets as a module, and the path will not be wrong after packaging