The IPM motors built with magnets placed inside the rotor body are attracting great attention in several variable-speed applications, such as electric vehicles and industrial and domestic appliances, where the most challenging requirement are high efficiency, high torque density, good overload capability, and extended speed range. This paper will develop A novel hybrid multi objective optimization method which combines the Taguchi method with different rotor pole topologies  for optimization of interior permanent magnet synchronous machines (IPMSMs). This method is capable to pre-optimize rotor pole topology and given multi objective optimization problem compared with the conventional IPM. The method is applied to maximize the power density and the efficiency of an IPMSM under constraints. In the optimization process, the power density of the IPMSM is significantly

improved and the volume of the IPMSM is minimized. However this method can improve the efficiency while increasing the power density. Finally, a rotor lamination prototype is manufactured to verify the feasibility of this method.