The stability of load side voltage supply in a DC microgrid is an important prerequisite to achieving a high level of new energy power consumption. To maintain the voltage stability of the low-voltage load side, the cascaded extended state observer is used to improve the estimation accuracy and speed of disturbance reconstruction. Second-order ADRC technology is introduced into the low-voltage side voltage regulation control. First, the system design of voltage regulation control strategy is realized based on a dynamic model of a low-voltage interface converter considering the existence of disturbance. Then, the improvement effect of the cascaded extended state observer on the disturbance reconstructed accuracy is analyzed in the time domain, and the total disturbance suppression performance of the system is analyzed in the complex frequency domain by using the linear equivalent framework. The influence of system model uncertainty on the dynamic performance is analyzed. In addition, Lyapunov theory is used to analyze the stability of the proposed voltage regulation control strategy. The analysis shows that the system is stable in engineering terms. Finally, the simulation results verify the correctness and effectiveness of the proposed voltage regulation strategy, and it has good resilience to the disturbance.