The present disclosure relates to a waterproofing method for an electronic device. In one example method, silane is coated on an inner wall of a first housing of the electronic device and an inner wall of a second housing of the electronic device. The first and second housings and a main board of the electronic device are assembled. Fluoride is injected into a cavity of the electronic device through a liquid inlet hole on the first housing. An integral continuous waterproofing membrane is formed on the inner walls of the first and second housings through chemical reaction between the silane and the fluoride.