The impeller is the core component of the pump, which is the main influence factor on the work efficiency. Under specific working conditions, if the impeller is not designed well, it will produce hydraulic loss and clearance loss at the pump inlet and blade. Then in the selection, we must choose a professional pump impeller manufacturer. It can be manufactured by CNC engraving, sand casting, transparent acrylic(PMMA/PC) 3D Printing. Fault cause ① The inlet water quality of the pump is poor. (High impurity content) ② The faucet filter or water inlet horn is too close to the sand or placed in the sand. ③ The conveying medium is bad, and the impeller material is improperly selected. ④ The impeller nut of the water pump is often loosened or loosened for a long time, resulting in loose impeller and partial grinding. ⑤ The pump often works under cavitation conditions, which increases the degree of cavitation damage of the pump.