The invention provides a portable hydrogen-rich water generation device provided with a three-port switching cover. The generation device comprises a middle casing, a support frame, a generator, the switching cover, an upper cover and a bottom cover, wherein the switching cover comprises a main body part, a first tooth, a second tooth and a third tooth are arranged at the main body part, the inner diameter of the first tooth is larger than that of the second tooth, the first tooth and the second tooth are arranged upwards, the third tooth is arranged downwards, the inner diameter of the third tooth is smaller than that of the second tooth, a first thread is arranged on the inner wall of the first tooth, a second thread is arranged on the inner wall of the second tooth, a third thread is arranged on the inner wall of the third tooth, and pitches of the first thread, the second thread and the third thread are different. Multiple teeth are selected and used by users, the device is convenient and quick, the switching cover can butt-joint containers with three models of ports, so that design diversification is realized, and requirements of water bottles with different aperture sizes and different models are met.