Aiming at the complex and cyclical variation of the internal fluid domain structure of the twinscrew compressor,a numerical simulation method for the flow field simulation of the 5~6 tooth twin-screw compressor was proposed.In the method,Scorg software and Pumplinx software were used to jointly analyze the flow field of twinscrew compressor,the negative volume phenomenon of moving mesh was avoided,and the problem of defining the negative and positive rotation modes by writing complex UDF functions was solved.The simulation results show that the fluid pressure acting on the rotor gradually increases from the inlet to the outlet in the axial direction,the compression and exhaust areas with higher pressure and the lower pressure suction area are bounded by the contact line,the pressure changes fluctuationally;the temperature change is non-steady-state,and the closer it is to the exhaust port,the more severe the change.The temperature and pressure of the twin-screw compressor outlet were tested.The test results show that the simulated data agree well with the experimental data.The research provides reference for the design and in-depth study of screw compressors.