The invention discloses a welding tool for pump valve mounting. The welding tool comprises a base, a rotating base, a box body, a first mounting base, a second mounting base, a dust collection box anda suction pressure tank. The rotating base is rotatably mounted in the top side of the base, a first hydraulic rod is mounted on the center of the bottom of the rotating base, sleeves are arranged atthe positions, on the periphery of the first hydraulic rod, in the rotating base, a mounting plate is arranged at the position, above the rotating base, of the telescopic end of the first hydraulic rod, guide rods are arranged on the periphery of the bottom of the mounting plate, the guide rods penetrate through the sleeves, one end of the rotating base is provided with a first mounting base, anda first servo motor is arranged on one side of the first mounting base. A pump valve is rapidly mounted and fixed, the pump valve can be conveniently subjected to multi-angle adjusting in the weldingprocess, the welding step is simplified, welding operation is facilitated, through stretching out and drawing back of a fourth hydraulic rod, dust treatment is finished, noise pollution is greatly reduced, and the whole treatment manner is environment-friendly, sanitary and free of pollution.