A new emergency control strategy for stability of power system， called A-S-C model， is proposed in this paper. The A-S-C model is implemented by the cooperation of three parts， i.e. Agent， Server and Client. In this model， the method based on antigen energy function（AEF） is employed to assess the stability of power system. Since AEF method can calculate system stability margin without the information of multi-machine equivalent and unstable equilibrium points， it performs faster than standard transient energy function-based methods. The turbine fast valving is chosen so as to maintain power system stability under system disturbances， the impact on turbine generator is decreased as well. The presented strategy is verified on the IEEE 39-bus test system.