The invention discloses a phase-to-phase spacer gallop bearing characteristic test system and test method. The test system includes a frame swing arm system and a base swing arm system; the frame swing arm system includes a frame swing arm rack, a frame swing arm bracket and a frame swing arm; the front end of the frame swing arm is coaxially provided with a frame swing arm rotation shaft; the front end of the frame swing arm rotation shaft is coaxially provided with a frame swing arm to-be-tested sample connecting device; the base swing arm system includes a base swing arm rack, a base swing arm bracket and a base swing arm; the front end of the base swing arm is provided with a base swing arm rotation shaft; and the front end of the base swing arm rotation shaft is coaxially provided with a base swing arm to-be-tested sample connecting device. With the phase-to-phase spacer gallop bearing characteristic test system and test method of the invention adopted, the movement mode of a wire spacer in an actual line gallop process can be simulated, so that the actual stress situation of the phase-to-phase spacer in the gallop process of wires can be analyzed, and therefore, damage rules and boundary conditions of the phase-to-phase spacer can be further summarized, and basic data can be provided for grid-connection detection of the dynamic bearing characteristics of the phase-to-phase spacer.