To solve the problems of low control precision and weak robustness of the traditional PID dual closed-loop control of a beam supply, a dual closed-loop control method using a PID controller in the inner current loop and a model predictive control (MPC) controller in the outer voltage loop is proposed. First, the structure and working mode of the novel dual full-bridge topology are analyzed. Then, a small signal model based on the topology is established, and the parameters of the controller in the inner current loop are designed, and the inner loop is taken as the controlled object to establish a prediction model and complete the design of the MPC controller. To verify the rationality of the MPC dual closed-loop control method, the MPC dual closed-loop control and PID dual closed-loop control are built in MATLAB for comparison. Simulation results show that compared with the PID dual closed-loop control, the MPC dual closed-loop control can effectively overcome the influence of load disturbance on output and improve the dynamic performance and anti-interference capability of the system.