The cross cardan shaft plays an important role in the transmission of torque and speed of screw drilling tools.However,the movement wear of the cross cardan shaft greatly reduces the transmission efficiency.In order to explore the motion law of the engagement surface of the cross universal joint shaft and the wear law of the anti-wear alloy block,the joint simulation physical model of the multi-body motion of the cross universal joint shaft and the calculation of the wear volume of the alloy block was established.According to Hertz contact theory and Archard wear theory,the contact boundary conditions of the simulation model were set,and the wear conditions were defined.The law of motion between mating surfaces and the law of contact force variation of conjugate motion pairs were studied.The movement path and contact force peak value of the meshing surface obtained from multi-body motion simulation were used as the boundary conditions for wear analysis of the anti-wear alloy block,and the influence of different structural forms on the wear volume of the anti-wear alloy block was studied.The results show that when the meshing is stable,the meshing surface will produce reciprocating sliding friction along the composite direction of tangential and axial direction,and the contact force presents a periodic fluctuation law.The different structure shapes and key structural parameters of the contact surface have significant effects on the wear amount of the alloy block,the use of concave double slope structure can effectively improve the wear resistance of alloy blocks.This research can provide a reference for the structural optimization design of the cross cardan shaft and the improvement of its wear resistance.