As one of the main frictional subsets of swash plate axial piston pumps, the slipper pair mainly work in complex and extreme environments. In this paper, basic governing equations of flow field in the slipper pair are established, and a finite element model of the slipper pair is constructed. After that, the flow field is simulated by CFD, and multi-field coupling of the slipper pair is analyzed. The changes in pressure and velocity fields of the oil under different working conditions and the effects of fluid pressure and temperature on the total deformation of the slipper pair are obtained. The results show that as working pressure increases, the pressure loss of oil in the damping line increases, and the number and size of vortices in the oil cavity increase. In addition, it is also found that the oil temperature has a greater influence on deformation of the slipper pair. The current work provides some technical support for design of the slipper pair, which is of great significance for improving overall performance of the slipper pair.