Aiming at the structural characteristics of the rotor during the working process of the twin screw compressor, the pressure and temperature fields generated during the working process of the compressor were comprehensively considered, and the fluidthermosolid coupling study of the screw rotor was carried out. Based on the finite volume method, the pressure and temperature fields generated during the compressor operation were solved. Through the numerical interpolation technique, the pressure and temperature fields were applied to the structured grid of the rotor, and the real force model of the rotor was established.The static balance equation of the rotor is further solved to obtain the displacement field and stress distribution of the rotor, and the proposed method was verified by using Lshaped largediameter buried pipeline. The research results show that the temperature field is the main reason for the large deformation and stress of the screw rotor, and choosing the appropriate speed can reduce the deformation and stress of the rotor. The research results have certain theoretical significance for the structural design and optimization of the compressor.