According to the distribution of the key points on the meshing line of the rotor profile of the twin screw compressor, the meshing line of the screw rotor profile was divided into five segments. The influence of the change of each segment on the performance parameters of the rotor profile was then discussed in detail. The resulted showed that the area utilization coefficient changes were associated with the area enclosed by the meshing line, which meant the sum of the area between the teeth of male rotor and female rotor changed to be larger. Only three segments of the sealing side of the meshing line had an effect on the area of the leakage triangle, and the changes of contact line length were complicated and closely related to the rotor profile.