Abstract: In order to meet the needs of modern bridges with large span and high bearing capacity, the cable specifications for bridges are gradually increasing. The increase in the diameter of the cable test piece for the fatigue test has higher requirements on the tonnage of the cable test machine. In this paper, the cable fatigue test device is designed from the actual demand. The device firstly applies the initial static load to the large tonnage cable through the jack, and then tests the tension amplitude of the cable through the small tonnage actuator. The research has saved the overall cost of the equipment, saved the energy cost in the operation phase, and improved the efficiency of the fatigue test.