The new powerful self-priming pump comprises a water pump main body, and the water inlet and the water outlet of the water pump main body are respectively connected with the water inlet elbow and the water outlet elbow, and the open impeller is installed in the impeller chamber of the water pump main body, below the water inlet elbow There is an inspection port for the inspection cover seal. Below the inspection port, there is a water discharge port sealed by a waterproof cover. The water outlet elbow is provided with a flap door, the open impeller is mounted on the pump shaft, and the pump shaft is mounted on the bearing body through the bearing. The bearing body and the pump body are connected by bolts, and there are two sets of mechanical sealing devices between the open impeller and the bearing, the mechanical sealing device is sleeved on the pump shaft, and the two sets of the mechanical sealing devices are respectively sealed by the inner machine The box and the outer box are enclosed. This new design makes the effect of the self-priming pump even better, and the suction stroke of the pump is significantly improved. It does not block, and it is also convenient to overhaul the impeller in the pump body.