Considering the influence of piston ring surface texture,elastic deformation and moving surface profile,a calculation model of elastohydrodynamic lubrication for piston ringcylinder liner friction pair of diesel engine was established.The influence of texture direction and roughness of the piston ring surface on air channeling and friction power loss were analyzed.It is found that with the increase of the engine speed,the piston air channeling and friction power loss will increase,resulting in the reduction of engine efficiency.The direction of surface texture of piston ring and cylinder liner friction pair affects the air channeling and friction power loss.There is a better improvement effect on the piston air channeling and friction power loss when the piston ring with a transverse texture is matched with the cylinder liner with a longitudinal texture.The surface roughness of the piston ring and the cylinder liner has a great influence on the sealing and lubrication characteristics of diesel engine.The air channeling is first decreased and then increased,and the friction power loss is first increased and then decreased with the increasing of the surface roughness of the cylinder liner.The air channeling and the friction power loss are both decreased with the increasing of the surface roughness of the piston ring in a certain range.