The longitudinal and lateral spans of the permanent magnet direct-drive (PMDD) inboard bearing bogie can be significantly reduced with the traditional bogies, providing an efficient solution for lightweight vehicles. However, the PMDD inboard bearing bogie does not need gearboxes, and the output torque of the motor directly is transmitted directly to the wheelset via a transmission hollow shaft, which could lead to the more severe electromechanical coupled vibration. Thus, the electromechanical coupled characteristics of the novel bogie should be investigated. In this study, an electromechanical coupled dynamic model of the PMDD inboard bearing bogie was established, and the model applicability was further analyzed. Subsequently, the dynamic performance of electromechanical coupled vibration was studied. The results show that the proposed model, compared with the traditional vehicle dynamic model, has better applicability to the electromechanical coupled vibration simulation. The electromechanical coupled interaction has a significant influence on the vertical vibration of the frame and motor together with the torsional vibration of the transmitted hollow shaft, especially at 6 times the fundamental frequency of currents. Moreover, the frame, motor, and hollow shaft vibrations under flux weakening control are more severe than those under MTPA control.