A three-dimensional deterministic numerical simulation model of mixed lubrication was established.The model adopted the unified Reynolds equation based on the system method and coupled the solid mechanics analysis,fluid mechanics analysis and contact mechanics analysis.Non Gaussian rough surfaces were generated,based on the mixed lubrication model,the effects of surface roughness amplitude,autocorrelation length ratio and texture direction on the sealing properties of O-ring reciprocating seal,such as friction,leakage rate,average film thickness and contact area ratio,were investigated by using the non-Gaussian rough surface.The results show that with the increase of surface roughness,the friction coefficient,average film thickness and leakage rate increase.When the Ra increases to a certain value and the contact area of the lubrication area is greater than 40%,the average film thickness and leakage rate begin to decrease.For a rough surface with transverse texture,there is an appropriate γ,which makes the comprehensive performance and lubrication state of the seal optimal.When θ =π/10,the friction coefficient reaches the minimum value.