A three-dimensional hydrodynamic lubrication model of the incompressible Newtonian fluid between two seal faces with single microdimple was built based on the full Navier-Stokes equation,the hydrodynamic lubrication of mechanical seal surface with the different bottom shapes of ellipse microdimple was studied,and the effects of different sections (rectangular, trapezoidal, triangular) of ellipse microdimple on load-carrying capacity, friction force and friction coefficient were analyzed.The results show that under the condition of the other factors with constant values, the microdimple with rectangular section has the best dynamic lubrication performance at the ratio of microdimple depth and end face clearance H*＜0.8, the trapezoidal section is the best choice when 0.8≤H*＜1.8,and the triangular section is preferred for selection at H*≥1.8.When the microdimple inclination angle α＝45°，the dynamic lubrication performances get optimal value for all ellipse microdimples with different section shapes. Further more,the trapezoidal section microdimple has a better hydrodynamic lubrication performance compared to the other section microdimples under the condition of different inclination angles.When 1.5≤γ＜2(γ is the ratio of length and width of microdimple), the ellipse microdimple with trapezoidal section has the best dynamic lubrication performance,but the rectangular section ellipse microdimple is the best at γ>2.