In view of the problems of stator electrically excited brushless synchronous motor（SEEBSM） with reluctance rotor, such as slow starting and low load capacity, the effect of adding cage bars inside the reluctance rotor on the electromagnetic performance and temperature is studied. The working principle and operation mode of the reluctance rotor with cage bars are described. The effect of the reluctance rotor with and without cage bars and different combination forms of cage bars on the rotation speed, and the effect of cage bars on the load capacity are studied by finite element method respectively. The threedimensional steadystate temperature field physical model is established, and the steadystate temperature rise of reluctance rotor with and without cage bars is simulated. The results show that the reluctance rotor with cage bars can greatly improve the starting performance and load capacity. Although the steadystate temperature rise of main structure increases significantly during load operation, it still meets the requirement of insulation class.