According to the demand of efficiency and operation safety in power system, it is extremely important to implement the risk evaluation of lightning disturbance for high voltage overhead transmission lines. However, there is no determined model and standard for the risk evaluation of lightning disturbance in transmission lines at home and abroad. Based on the improved analytic hierarchy process (AHP) and comprehensively considering the related factors of lightning disturbance risk, this article suggested a simplified model of lightning disturbance risk assessment, and carried out the example analysis. The results show that this model is effective and it could meet the requirements of the project application.