In order to improve the leakage of the reciprocating skeleton oil seal,a numerical calculation model for fluid lubrication of lip in the sealing zone was developed,and the radial deformation and surface roughness of the lip was considered.The hydrodynamic properties of the sealing zone was analyzed by solving the Reynolds equation,and the oil film thickness and pressure distribution in the sealing zone were obtained.The influence of excitation frequency and amplitude on the sealing performance was analyzed.The results show that with the increase of excitation frequency,the minimum film thickness is initially increased and then decreased in the sealing zone during the instroke and outstroke.The larger the excitation frequency,the worse the sealing performance of the reciprocating skeleton oil seal.The minimum film thickness is increased nonlinearly with the increase of the excitation amplitude in the sealing zone during the instroke and outstroke.The larger the excitation amplitude,the better the sealing performance of the reciprocating skeleton oil seal.Considering comprehensively,in order to improve the sealing effect,the reciprocating skeleton oil seal is suitable for small frequency and high amplitude working occasions.