In order to study the influence of actual working environment and working condition of diesel engine on wear of cylinder linerpiston ring,a thermodynamic and dynamic boundary condition simulation model and a dynamic load wear model for cylinder liner piston ring wear were established based on the actual working condition of a 12150 type diesel engine and its auxiliary system.A vehicle detection system was developed for diesel engine working condition.The wear and tear calculation process of diesel engine cylinder liner piston ring was established based on the joint simulation method.The wear distribution of cylinder liner was calculated and analyzed,and the experimental data of diesel engine of 400 h insurance period were tested.The results show that the distribution of surface wear of cylinder liner is uneven and has significant difference.The wear distribution is conical along the cylinder sleeve,and the wear depth near the top stop is the largest,followed by next the lower stop point,while the wear depth in the middle is smaller.The wear distribution along the circumferential direction of the cylinder liner is approximately elliptical,and the maximum wear depth is on the main and lateral thrust surfaces.The calculated maximum radial wear depth of cylinder liner is 479 μm,which is located at the crank angle 9° of the top stop.The actual measurement value of the maximum radial wear depth is 503 μm and the calculation error is 477%,the correctness of the calculation model is verified.The first piston ring (trapezoidal ring) has the largest wear effect on the cylinder liner,followed by the second ring,and the effect of the third ring is the smallest.