The invention relates to a single-circuit linear concrete double-rod middle-phased combined bird-preventing device and an application method thereof, pertaining to the technical field of prevention of bird harms in overhead transmission lines. The technical scheme is characterized in that the single-circuit linear concrete double-rod middle-phased combined bird-preventing device comprises a small-sized highly-magnetic reflective windmill bird-repellent device and multiple small-sized highly-magnetic stainless-steel bird thorns; the small-sized highly-magnetic reflective windmill bird-repellent device is placed above an isolator hanging point and absorbed on a plane of angle iron through a first strong magnet (16); the multiple small-sized highly-magnetic stainless-steel bird thorns are arranged around the isolator hanging point; and a second strong magnet is absorbed on cross arm iron steel. The single-circuit linear concrete double-rod middle-phased combined bird-preventing device and the application method thereof have the following beneficial effects: the device is small in size, low in weight and long in service lifetime and is not eroded; high magnetic material is utilized for installation; the device is convenient to detach and free from restrictions of mounting positions and directions; the device is movable; the single-circuit linear concrete double-rod middle-phased combined bird-preventing device is arranged above a concrete double-rod middle-phased insulator hanging point; therefore, birds are effectively prevented from building bird nests on ordinary bird thorns; maintenance staff can conveniently carry out maintenance; and a broad market space is obtained.