The harm of lightning can be divided into direct lightning strike and indirect lightning strike. Direct lightning refers to the conduction between the discharge of buildings or other surface objects and the Lei Yun, and a huge current flows at the struck place, resulting in huge electric effect, thermal effect and electromagnetic effect. And destroy the object that was hit. After lightning strikes a certain place, the electromagnetic waves aroused will spread outward, destroying or affecting nearby electrical equipment. The high potential generated after lightning strike will also enter the nearby buildings along the nearby wires, damaging the electrical appliances connected with it. So how to prevent the occurrence of lightning disasters? According to the nature and importance of buildings, it is the basic part of lightning protection to install lightning protection facilities in various buildings. When it is necessary to connect wires between buildings or establish communication and television links at ordinary times, the wires should be buried underground to prevent the introduction of indirect lightning. When it thunders, you should turn off the electrical appliances and disconnect the external power supply. When encountering a thunderstorm in the wild, you can't run under a big tree to shelter from the rain, because the big tree protrudes from the ground and is easily hit by lightning. You can find places or caves with lightning protection measures. If you can't find them, try to reduce the center of gravity and the contact area between the human body and the ground. You can squat down, put your feet together, put your hands on your knees and bend forward. If you wear a raincoat, the lightning protection effect will be better. Don't lie on the ground, in trenches or in pits. In particular, you should try to avoid answering your cell phone in thunderstorm weather, especially when you are traveling outside and in an open place. Be sure to turn off your cell phone in thunderstorm weather.