At 1350 hours on April 17, 2019, a mountain fire broke out in Qipanshan area, Shenyang City, Liaoning Province. The fire spread rapidly with the wind, resulting in power transmission and distribution lines tripping in the fire site and power outages in 5,500 surrounding scenic spots, factories, businesses and residents. Liaoning Electric Power Company of State Grid started the accident emergency plan quickly and coordinated the relevant departments. As a result, a total of 632 emergency teams and 113 emergency repair vehicles arrived at the fire scene for disposal. As of 19:00 on April 20, all the damaged equipment and power outage users had restored their power supply. This paper introduces the panoramic process of the accident from several aspects. For example, the grid structure of Liaoning power grid before the accident, the plan of Liaoning power grid to deal with the mountain fire, the process of mountain fire spreading, the sequence of line tripping affected by the mountain fire in the process of the accident, the change of the operation mode of the power grid in the process of the accident, and the process of power supply restoration after the accident. From the perspective of mountain fire warning, this paper describes the construction achievements of Liaoning Electric Power Ubiquitous-Perception in State Grid. This paper also explains the role of Internet of Things in disaster prevention and mitigation from the perspective of joint mobilization of electric power, fire protection, public security and other departments when mountain fires spread. Reasonable planning and operation mode of smart and strong power grid are introduced from the perspective of formulating effective fire prevention electric power plan, which can effectively reduce the power burden caused by force majeure. Load loss. Last but not least, the paper demonstrates the construction ideas of hub, platform and shared ubiquitous Internet of Things from the point of view of unified management of Liaoning Province, cross-regional operation and coordinated treatment of power grid faults.