According to situation of the accidents caused by windage yaw occurred in recent years,to reduce the probability of windage yaw flashover,the article analyzes the existing computation model of windage yaw flashover for Insulator string.For model’s defects,the article provides a new computation model of windage yaw flashover through the stress analysis and simulate by matlab considering stress’s Real-time changes to research the influence of the minimum air space.Finally,it conducts contrast analysis,which provides some useful references and theoretical basis for HV transmission.