Abstract: In this paper, the geometric model of the mechanical seal rings surface deformation is built, and micro surface morphology of the seal rings is simulated by the adaptive correlation function. Combining with simulation of rough surface, micro hydrodynamic lubrication model of surface deformation is also established. By programming with finite difference method and MATLAB software, the calculations of fluid film pressure distribution and fluid film thickness distribution of micro hydrodynamic lubrication of seal rings under a certain external load are successfully accomplished. A concrete example is calculated and analyzed. The detail research on the influences of face deformation and external load on the performance of mechanical seal rings lubrication such as fluid film thickness, friction, calorific value, leakage is carried out, and a series of performance curves are obtained and explained.