In recent years, the extreme natural disasters have caused serious damage to Fujian power grid.For changing from passive defense to active defense, the transformation of 500kV guaranteed grid can not be postponed. Based on the statistic of Fujian guaranteed power grid and the summary of tower collapse caused by wind disasters, some suggestions are put forward for the design standards of wind differentiation.Selecting the typical old standard tower, the full stress of linear tower and angle tower are analyzed under different conditions, and suggestions for the overall reconstruction or partial reconstruction of the tower are put forward. By establishing the evaluation factor set, determining the membership function of the factor set and matrix of confidence degree , the fuzzy evaluation method is used to quantitatively evaluate the priority of tower transformation. Taking Gangxia 500kV Line as an example, the results show that the line has 94 towers belong to the urgent reconstruction section, and the confidence coefficient is 4.