Geological disasters are one of the important causes of natural gas pipeline leakage accidents. If the emergency response measures are not proper, it will easily lead to more serious consequences. At the same time, geological factors will affect the emergency repair process and increase emergency risks. Therefore, dynamic risk assessment including geological factors is of great significance to ensure the smooth progress of repairs. In this study, by analyzing the influence of geology on pipelines and emergency processes and the static characteristics of the traditional FAHP (fuzzy analytic hierarchy process) method, a dynamic risk assessment index system based on geological factors is established, and update methods for dynamic risks of different types of indicators are given , The two combined to build a dynamic FAHP model. Taking the gas pipeline leakage caused by debris flow as an example, the real-time observation data of the pipeline and the changes in geological factors are used to illustrate the feasibility of the method. It also has some inspiration and guidance for the dynamic risk analysis and management of other emergency repair processes significance.