The utility model discloses a hydroelectric power plant no. 5 prevents control system, five prevent that control system and monitored control system are connected, include five -prevention, network controller, wireless router, be used for preventing first electron key of tool to lock matched with and second electron key with a plurality of no. 5, five -prevention is connected through an at least data line and monitored control system duplex, five -prevention and first electron key electricity are connected, five -prevention and network controller are connected, wireless router and network controller wireless connection, network controller and second electron key wireless connection. The utility model has the characteristics of can realize two -way pair of principal and subordinate's mode communication of five -prevention and monitored control system, reach five all standings of preventing, realize completely that five prevent the function, avoid the emergence of electric maloperation accident.