To improve the automation level of distributed generation, a hierarchical optimisation strategy is proposed in this study. The strategy consists of day-ahead dispatch and scheduling implementation by power control. The energy management framework about the multi-agent system is also designed. Given the collaborative gaming process between microgrid and distributed network, a day-ahead dispatch is used to minimise the general expenses. Moreover, considering security constraints, the secondary control strategy is proposed to realise the precise control of the active power, which is adaptive to voltage inconsistency. Besides, the consensus algorithm is utilised to trace the dispatch target of tie-line power by monitoring power deviation at the point of common coupling. Finally, a series of simulation verifies the effectiveness of the method proposed. The influence of communication delay is also discussed.