The common problem of distributed generation and microgrid accessing to distribution network is analyzed. Photovoltaic generation, wind generation, energy storage devices and electric cars are considered as random power supply. From special design for application scene, power matching for engineering application, external interface terminal, two-level and three-level topology, abnormal over voltage response, monitoring control and operation and maintenance, grid-connected and island protection, capacity penetration and generating capacity penetration and so on, the problem of random power supply accessing to distribution network is analyzed, cloud-layer-terminal three-layer architecture of plug and play random power supply is put forward. It achieves the goals of cloud-operation and maintenance plug and play, layer-orderly control plug and play, terminal-application scene, power matching for engineering application, grid security, information interconnection and maximum generating capacity penetration plug and play.