Abstract: The tripping accident of a 220 kV line maintained by State Grid Beijing Overhaul Company was preliminarily judged to be caused by wind deviation in combination with fault recording data and field conditions. Considering the air breakdown discharge distance, temperature, wind speed and other factors, analyze the impact of tower type, insulator string number and other parameters on the line wind deflection, calculate the wind deflection angle when the fault occurs, and comprehensively analyze the cause of the line fault. This paper further analyzes the influence of wind force, conductor load and stress area of insulator string on wind deflection angle. Finally, some measures are put forward to prevent and control the harm of line wind deviation in extreme weather.