This application provides a decorating assembly, a housing assembly, and an electronic device. Gas flows between the outside of the electronic device, the first gap, the first channel, the breathable space, the waterproof breathable film, and the first space to implement a quick balance between internal air pressure of the first space and external air pressure of the electronic device. In addition, the waterproof breathable film is installed on the base, and the waterproof breathable film covers the breathable space, to ensure that when the decorating assembly is applied to the electronic device, the waterproof breathable film can prevent external liquid of the electronic device from entering the first space through the breathable space, thereby ensuring that the electronic device has relatively good waterproof performance.