Abstract: A cluster analysis based power transmission line mountain fire risky area division method, which falls within the technical field of power transmission and distribution. Based on satellite fire point monitoring data, according to a proposed cluster distance index, a sample sequence is moved to another cluster and a cluster result is obtained by calculating the cluster distance index many times and moving same, so as to obtain power transmission line mountain fire risky distribution area division of a research area, serving as a basis for a refined forecast of power transmission line mountain fires and prevention and control of the power transmission line mountain fires. The method can be used to guide the deployment of fire extinguishing teams and fire extinguishing materials in a power transmission line mountain fire high-prevalence area, thereby enhancing the power grid mountain fire extinguishing capability.