DC-bus voltage stability of multi-micro-source DC microgrid system is an important index of power quality and one of the key factors that confine large-scale application.Aiming to solving the large fluctuation of the bus voltage, a master-slave coordinating control strategy based on the micro turbine as the main coordination unit is proposed.This control strategy making full use of the power regulation function of micro turbine, effectively reduces the fluctuation range of micro grid bus voltage and makes the output voltage more stable.At the same time, it reduces the number of batteries and the number of charges and discharges, and reduces the later maintenance cost of batteries.In this paper, hierarchical control, variable power control and master-slave coordinated control models are built in Matlab/Simulink respectively.By comparing the simulation analysis methods, the advantages of the proposed control strategy in reducing the battery input cost, maintenance cost and stable voltage are verified.