In order to improve the control performance of single-phase five-level rectifier, a dual closed-loop integrated control method based on non-delay power observer was studied. In this method, a virtual current signal reconstruction algorithm is proposed and combined with the improved generalized integration algorithm to construct a non-delay power observer, which is applied to the model predictive power control of the inner loop of the rectifier to observe the required power in real time, while the linear distraction control is used instead of the traditional proportional integration algorithm by linear distraction control in the outer voltage loop. The experimental results show that the time required for the control method to retrace the given value after the power mutation is shortened by 5~ 7 ms, and the voltage fluctuation on the DC side is reduced by 4. 4% and 4. 8% under the grid voltage drop and load disturbance conditions, respectively. Compared with the traditional method, this method not only reduces the overshoot of rectifier, improves the dynamic performance of the predicted power control of the inner loop model, but also effectively enhances the anti-interference ability of the voltage outer loop.