Based on PSCAD / EMTDC simulation software, the simulation of the overvoltage is carried out for the accident of two lighting failure in a substation near the cable outlet. Lightning point is located in the substation line into the second base tower. When the first lightning strike occurs, the number of insulators and the length of the outgoing cable on the overvoltage are simulated and analyzed. And the influence of different arrester configuration schemes on the over-voltage of the circuit breaker under the standby condition is analyzed. Simulation results show, as the number of insulators increases, the magnitude of the overvoltage will increase, the effect of different cable lengths on limiting overvoltages is quite different; when a second lightning strike occurs, the surge voltage can be effectively reduced by installing the surge arrester at the side of the breaker and the first base tower insulator in the substation.