The invention relates to a construction method for a multi-agent based micro-grid protection system. The multi-agent based micro-grid protection system which is constructed under an integrated system structure framework is divided into a device layer, an execution layer, a decision layer and a communication layer according to functions and layers. The device layer which is a system structure base layer faces a terminal device; the execution layer which is a connection step of the system structure undertakes information acquisition and command communication of a decision center and various device terminals; the decision layer which is a core step of the system structure achieves information integration and protects comprehensive decision; the communication layer which is an information circulation and transmission step is the basis for multi-agent implement and passes through the integral system structure; side current variable quantity based multi-agent micro-grid main and spare protective calculation decision methods are put forward. The construction method for the multi-agent based micro-grid protection system has the advantages of overcoming disadvantages of a traditional single-point information and two-point information based protective system, fully developing huge potential of the micro-grid main body communication structure in saving invest and providing possibility for future integration of multiple systems and protective relaying in future micro-grid.