A waterproof card holder includes a card holder frame and a cover plate located at top of the card holder frame. The waterproof card holder includes a sleeve integrated with and extending from an inner side of the cover plate and a through-hole penetrating through the sleeve and the cover plate. A waterproof mechanism is accommodated in the sleeve. The waterproof mechanism includes a main body, a first end portion located inside the sleeve, a second end portion protruding from the sleeve, and a waterproof ring located on a periphery of the main body and close to the first end portion. The waterproof ring and the sleeve form a sliding sealing structure therebetween.