The invention relates to a bus protection method applied to a complicated connection of a micro-grid. According to the method, with a section switch as a boundary, a bus with a fixed connection element in the complicated connection of the micro-grid is divided into different subsections; each subsection is provided with an independent bus protection; each subsection finishes the bus protection by an independent logic CPU (also called a logic module); and multiple sections of bus protections (multiple independent logic CPUs) form a complicated bus protectionwith no blind area. The multiple independent logic CPUs achieve information interaction in a data bus manner or a point-to-point data pipeline manner; and mutual starting and locking functions areachieved.