A tool for connecting busbars has an hydraulic cylinder driving unit and an electric control unit. A stationary portion removably is connected to a second busbar, a movable portion is removably connected to a first busbar a loading portion is for clamping connecting rods. The movable portion is movably connected to a first and second stationary shaft of the stationary portion, the movable portion is fixedly connected to the hydraulic cylinder driving unit by a movable shaft, the movable shaft is driven to slide axially with respect to the first and second stationary shaft by the hydraulic cylinder driving unit, the loading portion rotates around the second stationary shaft. It is achieved that a plurality of connecting rods are simultaneously mounted to busbars and that two busbars are connected in a form of butt-and-butt connecting.