The invention discloses a self-priming water cup, which comprises a cup body and a cup cover. Equipped with a water purification device, the lower part of the cup body is provided with a fixed frame, the interior of the fixed frame is provided with an anode electrode and a cathode electrode, a water-permeable diaphragm is arranged between the anode electrode and the cathode electrode, and a groove is provided at the lower end of the cup body , a connecting rod is provided in the middle of the groove, and a fixing device is provided at the lower end of the connecting rod. The fixing device includes a shell and a suction cup. Connected with the upper side of the movable plate, the right side of the housing is provided with a ventilation pipe, the lower end of the ventilation pipe communicates with the suction cup, and the other end of the ventilation pipe communicates with the upper part of the cavity. The invention has the advantages of simple structure, convenient use, stable placement, convenient pick-up, and can improve the quality of drinking water.