Abstract: The transmitter and actuator damage and measuring signal fluctuation of outdoor instrument and control (I & C) equipment caused by lightning happen frequently in the power plants of Zhejiang Province, especially in Yueqing Power Plant, which has seriously threatened the security and stability of the unit operation. The statistical analysis and investigation on the issue are carried out by the plant. Based on the risk assessment on the lightning stroke on the outdoor I & C equipment, the lightning protection components are developed and put into use. As the grounding system is being improved, the situation is changing positively. Through the analysis and treatment on the lightning stroke events, the technical measures of anti-lightning for the I & C system are proposed for reference in the industry.