Hybrid electric drive is an important research field of vehicle technology and is the basis for the full-electric high-mobility multipurpose ground vehicles，while the in-wheel drive system is the power core of the in-wheel drive vehicles，of which the performance of the in-wheel motor is particularly critical. The state-of-the-art technology and development trend of in-wheel motor is overviewed. The prospects for the development of existing novel permanent magnet motors in the field of in-wheel drive are outlined based on the requirements of high torque and wide speed range of in-wheel motors for electric drive vehicles. The key technical issues of permanent magnet in-wheel motors are summarized. The future developments are foreseen. A comprehensive review is made on the theoretical researches and practical applications of in-wheel motor drive system at home and abroad，with a view to providing a reference for the development of future motors used in electric drive vehicles.