The popularity of smartphones, watches and other electronic products with touch screens makes manufacturers compete to introduce differentiated products in order to attract consumers. At present, a bright spot in the market is to design the shell of electronic products into a curved surface, that is, the shell is no longer flat, but has a three-dimensional surface. Electronic products with curved surface design can better fit the user's hand and improve the comfort of grip and manipulation. If the watch shell is designed as a curved surface, it can be better matched with the wrist to improve the comfort of wearing. And the surface design of the display shell, its display content has a more three-dimensional sense, so as to enhance the visual effect. Glass is more popular as a shell material for electronic products because of its texture. The traditional method of installing decorative film on flat glass is usually roller or airbag processing, but this method is no longer suitable for installing decorative film on 3D glass, because the above processing method can easily make the decorative film wrinkle at the edges and corners of 3D glass surface, which affects the processing effect of 3D glass.