Abstract: Using a moving mesh method, a three-dimensional transient numerical simulation model for a rolling piston compressor chamber was established. Compared with a theoretical work cycle, the numerical results indicated that the model reflected the main process of a rolling piston compressor, and can be used to study a pump chamber flow field. Gas flow in a pump chamber was simulated, providing considerable detailed information of the pump chamber flow field. Flow phenomena and flow field in the pump chamber were analyzed, and primary characteristics of the flow field during compressor intake, compression, and exhaust were determined. The results provide a basis for structural optimization and further study in rolling piston compressors.