In civil engineering, the aseismic theory based on displacement generally is used in vibration damping design. This theory cannot be applied to reinforced concrete (RC) arched bridges, however, due to the tremendous rigidity of these bridges. To address this situation, a new vibration damping method called an “intelligent aseismic control system with changed rigidity of RC arched bridges” is suggested. With this method, the system of the main arch will be changed, the rigidity lowered, the deformed capability increased, and the displacement and stress can be under double control. When an earthquake occurs, the RC arched bridge stress can be lowered while the displacement is not obviously increased with this method.