Abstract: Most liquid lubricating systems are inevitably supplied with lubricant containing contaminant particles. It is certain that some of these particles are suspended in the oil, that is, the size of the solid particle is smaller than the oil film thickness. In this paper, the effects of the suspended particles on the oil film pressure of cylinder-piston ring were mainly studied. In recent years, the lattice Boltzmann method (LBM) has been developed as an alternative to the conventional CFD (Computational Fluid Dynamics) methods. Unlike conventional numerical schemes based on discretization of macroscopic equations, the LBM is based on the statistical physics and describes the microscopic picture of particles movement in an extremely simplified way, but at the macroscopic level it gives a correct average description of the motion. It has been widely used to simulate the two-phase flow. The paper is aimed to study the influence of solid particles on the oil film pressure of piston ring based on L. The lubricate oil with suspended particles was regarded as the two-phase flow. The movement of the lubricate oil with solid particles is described with kinetic equations of distribution function of particles. A discrete Lattice-Boltzmann model of cylinder-piston ring was built in the domain of piston ring lubrication from the perspective of flow field. The implementation of boundary conditions for LBM is very important and has great effect on the accuracy and the stability of method. The bounce-back scheme was used in fluid-solid boundary and wall boundary treatment. The Reynolds boundary condition in the Lattice-Boltzmann Method was developed for the cracked oil film. By programming simulation, the influence of solid particles on the oil film pressure of piston ring was studied by researching the flow of the lubricant with solid particles based on LBM. The effect of particle location, shape and number on the oil film pressure of piston ring at certain crank angle was analyzed. The influence of solid particles on the oil film pressure of cylinder-piston ring was studied at different crank angle. Oil film velocity of lubricant was simulated base on LBM, and the simulated results were compared with the experimental results. The results of simulation agreed with experimental result well. It was shown in the results that the effect of the particle on the film pressure in piston ring lubrication was more significant, if the distance between the ring and particle center was closer. The variation of oil film pressure was 34.6% compared to the oil film pressure without particles. Conversely, the effect on the pressure was slight when the distance was greater, and the variation of oil film pressure was 11.2% compare to the oil film pressure without particles. When the thickness of particle was same, the influence of the longer particle on the oil film was more significant. The effects of particles on the oil film pressure were slight during the suction stroke and compression stroke. The variation of oil film pressure was 2.85% compared to the oil film pressure without particles at crank angle φ=320°. Then, the influence of particles on the oil film pressure of piston ring was more significant during the power stroke. The variation of oil film pressure was 3.95% compare to the oil film pressure without particles at φ=450°. Moreover, the experimental phenomenon that the abrasion was severe at dead centers of the engine, was theoretically analyzed. The study will provide theoretical reference for structural optimization of cylinder-piston ring.