The invention belongs to the technical field of textile fabrics, and particularly relates to a waterproof cloth for a low-frequency electromagnetic physiotherapy mat, as well as a preparation method and an electromagnetic physiotherapy mat. The waterproof cloth consists of a cloth base and a waterproof coating attached onto the external surface of the cloth base, wherein the waterproof coating consists of polyurethane, modified P type zeolite and ethyl acetate in the weight ratio of the polyurethane, the modified P type zeolite and the ethyl acetate being 3:(0.5-1):(1-10), and the average particle diameter of the modified P type zeolite is 0.5-1.0 microns. The waterproof cloth disclosed by the invention has a favorable waterproof property, the contact angle of the waterproof cloth reaches 130 degrees or above, the antibacterial time of the waterproof cloth is long, and after the waterproof cloth is washed for 50 times, the antibacterial rate of the waterproof cloth is still 70% or above; besides, cotton cloth is used as a cloth base of the waterproof cloth, so that the degradation time is short, and the waterproof cloth is free of toxins to human bodies, is simple to prepare, and is suitable for wide popularization and application.