Aimed at the typical characteristic of distributed generation system， an explicit-implicit hybrid integration algorithm suitable for distributed generation system is proposed. Power electronic components in the distributed generation system have relatively fast dynamics， while distributed sources such as fuel cell， wind turbine， micro gas turbine， batteries etc， possess relatively slow dynamics. Based on this characteristic， a division principle for stiff system is designed. For power electronic components with fast dynamics， implicit integration algorithm is used and for distributed sources with slow dynamics， explicit integration algorithm is adopted. The advantages of fast calculation speed of explicit integration algorithm， numerical stability of implicit integration algorithm， and the adaptability to the variable structure operation of microgrid are all considered. Finally， the correctness and effectiveness of the proposed algorithm is verified by simulation.