Thrust bearing is one of the most important components in esPCP system, which determines the lifespan of the whole system under the restriction of some factors such as the depth of downhole unit, the viscosity of petroleum oil to be pumped. To increase the high temperature bearing ability of the bearings under the limitation of radial size, the damage reason of pre-applied bearings was analyzed. Some different modified plans were put forward from two aspects of structure and material. Contact problems were researched for different plans with finite element analysis software of ANSIS. Comparison of results shows that, in the well of 5½" tube, the optimum selection is ball thrust bearing with 8 balls of radial size of 10mm without keeper.