In order to reduce the impact of dense transmission channel outages due to lightning strikes on the operational safety of the power system, this paper proposes a framework of active defense dispatching strategy for dense transmission channel based on lightning warning information. We first establish a comprehensive evaluation model of transmission line unexpected outages based on analytic hierarchy process, then rank the importance degree of the line according to the comprehensive impact index, and fuse it with lightning warning information to provide an essential basis for predicting the set of scenarios. Second, a preventive-emergency two-stage stochastic optimal dispatch model is established to carry out power flow transfer in the preventive dispatch stage and take load shedding to reduce outage losses in the emergency dispatch stage. Finally, a case study verifies that the proposed method is effective in reducing the total system losses in case of dense transmission channel outages due to lightning strikes. 1 1 Supported by Science and technology program of SGCC (State Grid Corporation of China): Research on intelligent monitoring and protection capability improvement technology of UHV dense channel to cope with extreme environmental conditions (524625210017).