Compared with the traditional conventional double closed-loop control method, in order to improve the drawbacks such as low current accuracy, poor dynamic response, poor output voltage stability and low immunity to interference, in this paper, according to the structure and characteristics of the circuit itself, the corresponding circuit model is established, and the relationship of the duty cycle of the current ripple is found to be further investigated after. In this paper, in order to realize the current sharing and low ripple, the first-order self-resistant control strategy (LADRC) is proposed to incorporate a state observer in the system to estimate the compensation relationship of duty cycle between the phases. The effects of low current sensor accuracy and high design cost are reduced. Finally, the simulation results on the MATLAB platform show that the current equalization effect is significantly improved under different loads and voltages, and the equalization current error is reduced by 6.87%.