Abstract: It is helpful to grasp the approaches and ways of lightning, and understand the regularities of lightning disaster by analyzing the lightning accidents, thus more effective measures can be taken for lightning protection. Firstly, the lightning location data in the area of lightning strike were analyzed according to a lightning disaster on a breeding farm in Xitiangezhuang Town, Miyun County, Beijing on July 1^st 2014. According to the rolling ball method, the authors judged whether the breeding farm was in the range of direct lightning protection. Then the step voltage and lightning electrostatic induction voltage at the breeding farm were calculated. The results showed that: the livestock was killed by the lateral flashover and the touch voltage from lightning. The high voltage was inducted by lightning electrostatic in the metal shed. However, the supporting steel structures of metal shed had no grounding so that the releasing channel of the induced charge was not smooth. There was a potential difference between the ground and the metal shed, therefore the lateral flashover happened. In addition, when the livestock was exposed to the steel structure, the high potential released through livestock to the ground. In the end, the corresponding protective measures were put forward to reduce or avoid similar accidents in the future.