In order to ensure that the series micro-networks interconnection and the islands of two kinds of operation modes can switch smoothly, a coordinated control method of using a sub-system composed of series-connected micro-source and super-capacitor as the main source and the flywheel battery for keeping uninterrupted power supply is studied. First, the structure of the system is briefly described. Secondly, the control methods of micro-source and complex energy storage in micro-grid mode switching are analyzed. Finally, Matlab/Simulink simulation analysis based on the micro-grid with two series subsystem is made. The results show that the micro-grid can be maintained at good voltage and frequency stability in mode switching because of complex energy storage control function, thus the effectiveness of control method is verified. This work is supported by Youth Science Foundation of Gansu Province (No. 17JR5RA345).