In order to study the effect of small solid particles in lubricating oil on the lubrication performance of liner/ring,〖JP〗a discrete model of piston ring lubrication with solid particles was established by using Lattice Boltzmann method (LBM).According to the lubrication characteristics of piston rings,the boundary conditions of oil film were processed.The influence of single and multiple particles on lubrication was studied,and the influence of particle shape,distribution and position on piston ring lubrication was analyzed.The results show that the oil film pressure is greatly affected when the particles are close to the piston ring.When the particles are located near the fracture boundary of oil film,the existence of particles leads to negative pressure in the oil film pressure field and return zone,which may lead to particle accumulation and wear of liner.Whether single particle or multiple particles will cause an obvious sudden change of oil film pressure,and the lubrication area affected by multiple particles is larger.This sudden change of oil film pressure will lead to the poor stability of piston ring movement,thus affecting the performance of the engine.