The cavitation damage of the cylinder block and cylinder liner of the loader causes cracks and even through holes, which results in the cooling water entering into the cylinder and the oil. The main cause of cavitation is the vibration of cylinder liner. When the piston reaches the top dead point, the direction of the lateral pressure changes, the piston from the cylinder side to the opposite side of the cylinder, the phenomenon of piston pendulum. As the piston and the cylinder liner between the heat gap, so the piston swing is a shock. This shock causes strong vibration of the cylinder liner. When the vibration of the cylinder wall, alternating tension and compression occur in the water chamber, so that the local water pressure and the vacuum bubble are generated in the water near the outer wall. In high vacuum under the effect of the cooling water evaporates into the vacuum bubble and bubble bubble, some occur in the cylinder wall or in a tiny pinhole, the effects of vibration by impact pinhole. Serious cavitation bubbles under high pressure shock and rupture, produces pressure shock wave in the rupture zone near the pressure up to dozens of atmospheric pressure and the impact of cylinder wall, repeated impact such frequent, makes rapid damage of cylinder surface. In order to prevent cavitation, the common method is: reduce the gap between the cylinder and the piston, thereby reducing the cylinder vibration; the length of the piston skirt; increase the cooling water flow velocity, flow direction and structure improvement of cooling system; increase the support cylinder stiffness; cylinder liner material and process improvements, in order to improve the anti cavitation ability and so on.