Abstract: Considering the high ratio of live load to dead load, this paper proposes using smart cables in the cable-stayed bridge. Under various load conditions, the deflection and strain of the main girder can be controlled in the allowed range when the employed actuator system can contract or release the smart cables in real-time. Based on a multilevel control algorithm, the active control experiment of a cable-stayed bridge model that used a digital control system was investigated, in which the mid-span strain is used as feedback. The influence of motor speed parameters setting on the smart system performance was examined and the influence of multi-level strain limit and motor speed parameters setting on the smart system performance was also studied. The result shows that the control ability of fast loads can be improved, and the energy consumption of slow loads can be reduced simultaneously, by means of classifying the actuator speed and the limited strain range.