In order to reduce the output voltage harmonic content of microgrids and utility grid harmonic pollution, a kind of microgrid whose micro source inverters are connected in series is proposed. Firstly, the system topology structure, double Fourier expression of output voltage and the characteristics of the system are introduced in detail. Secondly, corresponding solutions to problems of DC link voltage fluctuation, power distribution and micro source real-time pitch cutting are put forward. Lastly, according to the mathematical model of the micro source, operating characteristics of the system are simulatecl and analyzed using Matlab/Simulink software. While reducing the output harmonic content, the special structure of microgrids solves the problems of circulation and frequency difference. The system improves the acceptance ability of traditional grid for distributed power, providing a new idea and new direction for all-round development of microgrids.