The invention discloses a control method of a bridge anti-collision device. The bridge anti-collision device comprises a bridge terminal and ship terminals, wherein the bridge terminal is arranged on a bridge, and the ship terminals are arranged on ships, the bridge terminal comprises a first wireless transceiver, a first microprocessor, a first GPS position finder, a first storage and a plurality of directive antennas, wherein the directive antennas are electrically connected with the first wireless transceiver respectively, the first microprocessor is connected with the first wireless transceiver, the first GPS position finder and the first storage, and the ship terminals comprise omni-directional antennas, second wireless transceivers, second GPS position finders, second storages, display screens, second microprocessors and alarms. The bridge anti-collision device has the advantages that early alarms can be given to the ships near the bridge in advance, alarming data information accuracy and the anti-collision effect are good, and traffic orders on the bridge and normal life of people around the bridge can not be disturbed.