The bridged icing flashover accident of insulator strings is one of the major factors which affect the safe operation of overhead transmission line. The electrically neutral insulator strings and wire icing data over the same period were used in this paper to comparatively analysis the icing weight among different types of insulator which included glass, ceramic, complex insulators, and their relationships with wire icing weight. Meanwhile the relationship between insulator strings bridging connection and standard thickness of wire icing was discussed.