In order to adapt to complex scenario of the dynamic transfer of the dominant weak section which is characterized of leading instability mode of the dominant generator cluster under the large disturbance impact of power network, corresponding transient stability control strategy is needed. Based on the method such as identification of the key branch in the weak AC section and distinguishing the stability according to the geometrical feature of the key branch’s disturbed trajectory, aiming to the complex disturbance scenarios that the weak AC section with oscillation center located will migrate after disturbed, a transient stability control strategy adapting to this scenario is proposed, which uses the real-time disturbed electric quantities of the key branch as the information source. Simulation results got from the HVDC and AC hybrid system verify the effectiveness of the control strategy. This work is supported by National Natural Science Foundation of China (No. 51207143).