According to the structure characteristics of the wet clutch friction pair,the rough contact of the clutch friction pair surface was studied,the average flow model was improved,and the modified Reynolds equation was established to calculate the change rule of the oil film pressure and the oil film thickness during the engagement process.Based on the Greenwood Tripp contact model,the friction heat equation of the friction pair was established.The variation laws of oil film thickness,relative sliding speed,joint oil pressure and friction torque of wet friction pair in the process of sliding were simulated.The friction heat produced by the shearing action of micro convex body and oil film in the process of sliding of friction pair was analyzed.It is found that the radial distribution laws of them are linear and parabola.The effects of joint oil pressure and relative sliding speed on friction heat produced by micro convex body and oil membrane shear were studied.The temperature field experiment of steel sheet was carried out to verify the simulation results.The results show that the larger the joint oil pressure is,the larger the friction heat produced by the shear action of the micro convex and the oil film in unit time is,and the earlier the time of the friction heat peak produced in unit time is.The larger the relative speed difference is,the larger the friction heat produced in unit time is,and the oil film is the opposite,and the change of the relative speed has no effect on the time of the friction heat peak produced in unit time