Abstract: In order to improve the response speed and control performance of the three-phase Vienna rectifier in a complex environment, a model-free predictive direct voltage control(MFPDVC) algorithm is proposed. Firstly, by analyzing the mathematical model of the three-phase Vienna rectifier, an ultra-local model independent of the physical parameters of the system is constructed to enhance the robustness of the control system. Secondly, the ultra-local model was discretized to obtain the system prediction equation, and the cost function including voltage, power and midpoint potential is designed to control multiple targets with a single loop, breaking through the bandwidth limitation of the inner and outer loop of the traditional double closed-loop cascade control structure and improving the transient response of the system. Finally, the Luenberger observer is designed to observe the unknown part of the voltage and power ultra-local model, and real-time compensation prediction model is used to further improve disturbance resistance performance. Sequentially, the model-free predictive direct voltage control algorithm is realized. Simulation and experimental results show that the proposed strategy has better robustness and dynamic and steady-state performance than traditional finite set model predictive power control method.