Abstract: In the operation of DC micro grid, the uniform load distribution is beneficial to the stable operation of the system and prolongs the service life of the system. In order to solve the influence of line resistance on traditional droop control in dc micro-grid, a resistance detection method based on ripple analysis was proposed based on the structural characteristics of the dc micro-grid system. The high-frequency harmonic component of microgrid output current and voltage is mainly from the transistor switching frequency. By analyze the high-frequency harmonic component of the voltage and current detected by the converter, the impedance information was obtained, and then the droop control was compensated base on it. In this paper, the compensation method was extended to the application of multiple devices in parallel. This method does not directly operate the system, so it had done no harm to the power quality. Finally, the feasibility of the proposed method in normal working conditions and its effectiveness in the case of communication interruption, load mutation were verified by RT-LAB hardware in loop simulation.