A welding device for engineering machine parts comprises a machine body device and a material stirring device. The machine body device comprises a rack, a pedal, a hopper, a spring, a belt, a front roller, a rear roller, a first gear and a first one-way bearing. The material stirring device comprises a material stirring frame, a material stirring roller, a cam, a rolling wheel, a pawl frame, a pawl, a second gear and a second one-way bearing, and the material shifting device is fixedly connected with the front portion of the rack. Vertical plates in bilateral symmetry are arranged on the rear side of the rack, rear roller holes are formed in the rear sides of the vertical plates and penetrate through the two vertical plates, front roller holes are formed in the front sides of the rear roller holes and penetrate through the two vertical plates, a front plate is arranged on the front sides of the vertical plates, a discharging groove is formed in the lower portion of the front plate, a receiving frame is arranged in the middle of the rack, a hopper opening is formed in the upper portion of the receiving frame, a clamping groove is formed in the right side of the hopper opening, a stand column is arranged on the front side of the rack, and a guide hole is formed in the middle of the stand column.