The thermohydrodynamic lubrication properties of overturning slipper pair considering elastic deformation and thermal deformation are studied. The effect of thermal deformation and elastic deformation of slipper surface on the thermoehydrodynamic lubrication of slipper pair under work conditions of different load pressure,shaft speed and inlet temperature is discussed mainly. The lubrication properties of slipper pair is analyzed by using Reynolds equation and film thickness equation based finite difference method. The slipper deformation is calculated by finite element method. The film temperature distribution is calculated by energy equation and heat conduction equation. The results show that there is a convex shape of oil film temperature and pressure distribution in slipper pocket and edge. Oil film temperature cross slipper radius decreases from the slipper pocket to the edge of slipper. The high shaft speed,load pressure and inlet temperature are,the more obvious damped oscillation of oil thickness will be. The fiction torque increases with decreasing oil film thickness. The peaks of fiction torque and oil film thickness exist at the high-pressure and low-pressure alternate region of piston pump.