A new method is presented to restore the power system based on the multi-agent technology， combining with the strategy for island system operation. This method sets a local management agent or a remote management agent in each distribution generation island， and the two agents together with the load agent and generator agent to form a multi-agent system. When the whole power system collapses， the hydropower generating units will supply the initial power as the black start electrical source. According to the black start plan， the power system is restored through the coordination between the agents in the multi-agent system. This paper introduces the basic principle of restoration method based on the multi-agent technology， structure of the multi-agent system， function of each agent， and theoretical process of fault recovery. The proposed method is validated by simulation results.