When the effective cavitation margin of the water pump device is less than the necessary cavitation margin of the water pump, and the local pressure inside the pump decreases to the saturation vaporization pressure at that liquid temperature, the gas nuclei existing in the impurities, small solid particles, or gaps at the liquid interface (the contact surface between liquid and solid) in the liquid rapidly grow into bubbles, and they reach the high-pressure zone with the water flow and quickly collapse under the compression of the surrounding liquid. In the bubble collapse zone, the metal surface is subjected to a water hammer force with a frequency of tens of thousands of times per second, and it acts on extremely small areas, so its stress can reach several thousand atmospheric pressures. Frequent application of such large stresses causes plastic deformation and hardening of the metal surface layer, resulting in local fatigue and small cracks, which promote the development of cavitation. Causing the metal components to be broken and peeled off. Cavitation may occur on the back and front of the impeller blades, as well as between the outer edge of the impeller and the wall of the impeller chamber. Usually, pump cavitation reduces the flow rate, head, power, and efficiency of the pump, causing unit vibration and noise, shortening equipment life, and affecting engineering safety. The situation is even more severe for water pumps that extract water from streams with high sediment content.