In this paper, a collaborative grid scheduling strategy based on swarm intelligence is proposed to solve the problem of insufficient operational flexibility of active distribution network under high penetration rate of new energy. By dividing the distribution network into several independent and autonomous grids and simulating the crowd intelligence behavior in nature, the strategy realizes the optimal allocation and cooperative scheduling of distributed energy, energy storage devices and controllable loads in each grid. At the same time, considering the characteristics of mutual benefit among the grids, the flexibility evaluation index is used to guide the resource redistribution, which effectively improves the operational flexibility and economy of the distribution network. In addition, this paper also establishes a robust optimization model of multi-microgrid distribution system considering the uncertainty of source load, and realizes the distributed coordination optimization between distribution network and microgrid based on ADMM algorithm. The effectiveness and feasibility of this strategy are verified by numerical examples.