Twin screw compressor is the mainstream device of the combustible gas and other media recovery and transportation in industrial field. For the defects of the oneway force of the twinscrew compressor in use, a balanced twinscrew compressor which could achieve the opposite configuration of the workload was proposed. In order to study the internal flow field characteristics in the working process, the fluid numerical model was established based on the working principle and basic structure of the balanced twinscrew compressor, and the numerical simulation of the balanced twinscrew compressor working process was carried on by SIMPLEC algorithm and RNG/κ-ε turbulence model of CFD. The distributions of fluid pressure, velocity and density in the process of balanced twinscrew compressor were obtained. It provides reference for the engineering application of balanced twinscrew compressor.