The strain and stress of stator and bushing in multilobe screw drill were analyzed theoretically to gain its deformation law and stress distribution. Meanwhile, pressure and pressure difference coupling were imposed to research the deformation and stress of rubber bushing caused by meshing under real working condition. The mechanical property and the superiority quantization of isowall thickness stator and bushing were acquired by contrasting the results of finite element calculation.The result shows that the method for the deformation of isowall thickness stator bushing is 50% smaller than the ordinary one under the same pressure.Under pressure and pressure difference coupling,the critical contact pressure of isowall thickness stator bushing is bigger than the ordinary one,reduing speed slower than the ordinary one.It can improve the working and sealing performance, which provides the theoretical foundation for multilobe isowall thickness screw drill optimum design.