The invention relates to a time-varying damage bridge experiment device. The device comprises a main bridge panel. The main bridge panel is provided with several damage holes spaced apart by a certaindistance. Electromagnets which are cooperated with the damage holes and whose magnetism can be controlled through energization and outage are arranged in the damage holes. The upper end surface of the main bridge panel is provided with a sensor used for measuring a bridge deformation displacement, a deformation speed and a deformation acceleration. The upper end surface of the main bridge panel is provided with a movable dolly capable of loading an object. The front end surface of the movable dolly is provided with a draw hook. The draw hook is provided with a pulling rope. One end of the pulling rope is fixed to the draw hook. The other end of the pulling rope is provided with a variable-speed traction machine. The invention also relates to the experiment method of the time-varying damage bridge experiment device. In the invention, the conditions of a bridge when being subjected to single or multiple time-varying damages, and when load quality changes and a load speed changes can besimulated, and a corresponding deformation displacement, and deformation speed and deformation acceleration data can be detected.