Aiming at the problem of torque coordinated control between motor with high-frequency response and engine with low-frequency response of hybrid electric vehicle (HEV) during mode transition process, the mechanism of its coordinated control problem is deeply explored, and the essence of dynamic coordinated control strategy (DCCS) through torque coupling analysis is also revealed, namely, motor torque compensation control. Then a series of domestic and international researches on multi-power sources coordinated control are systematically summarized from the establishment of electromechanical transmission (EMT) system model, mode switching process analysis, engine-clutch-motor coordinated control strategy based on torque estimation and speed feedback tracking, as well as the controller robustness analysis under system parameter perturbation and external disturbance. Finally, the key issues on the rapidity, adaptability, and experiment of torque coordination control which need to be solved in the subsequent researches are pointed out clearly.