Compared with conventional PDM, uniform-thickness PDM has wider application range with long service life and high torque. The related research on uniform-thickness PDM is still in the stage of theoretical analysis. This paper introduces the theoretical performance and the actual working performance of PDM, analyzes the performance characteristics of 89mm uniform-thickness PDM based on the laboratory tests and field experiments and establishes the calculation models of volumetric efficiency, speed, torque and power, the results verify the accuracy of the theoretical performance of the uniform-thickness PDM, which could provide guidance and reference for uniform-thickness PDM design and drilling tools selection.