The development of variable frequency speed regulation three-phase permanent magnet synchronous motor series products with IE4 efficiency grade is introduced. In order to improve the design accuracy and shorten the design cycle, the electromagnetic design of this series of products adopts the design method based on the combination of field and circuit. On the one hand, it improves the rationality of the design, and the product performance index fully meets the standard requirements. On the other hand, the reasonable magnetic circuit design improves the power density of the motor and reduces the volume of the motor. Compared with the general series products, this series generally reduces 1~2 frame numbers and reduces the material cost. Through prototype trial production and type test, the rationality of series motor design is verified, which provides a reference for IE4 general variable frequency speed regulation three-phase permanent magnet synchronous motor research in China.