The invention provides a micro-grid structure and a power quality control method thereof. The micro-grid structure comprises a plurality of distributive micro sources and a common busbar. The distributive micro sources are parallelly connected to the common busbar through corresponding feeder lines and respectively connected with nonlinear loads and linear loads, and the common busbar is connected with the nonlinear loads and the linear loads. A first switch is in parallel connection with an isolation transformer to control an input state of an inverter for compensation. A static switch which is an option switch is arranged at a point of common coupling, and option ends of the static switch correspond to a large power grid side and a ground terminal respectively.