Based on the electrically driven inertial vibration exciter, a twopoint excitation fatigue test system of wind turbine blade was constructed. The virtual master synchronization control algorithm was put forward. The PID algorithm was used to design the error compensator, then the stability of the control algorithm was proved by using Lyapunov function. The control simulation model was established, and the convergence and the robustness of the control algorithm were analyzed by numerical simulation. Finally, the effectiveness of the control algorithm of electromechanical coupling was verified. The results show that the control algorithm can make the exciter follow quickly, the fluctuation of phase difference between the exciters is very small, the blade amplitude is stable, and the stable and effective loading of wind turbine blades is realized.