Title: Sheyang County coastal Lot transmission line insulation options Abstract Analyze the causes of transmission line insulation pollution flashover, the transmission lines of research Sheyang County coastal lots geographical location, climate characteristics and natural, industrial, Artificial pollution situation, summed up Sheyang county power transmission lines Pollution Flashover status of work. 2009 to 2011 Sheyang County power company under the jurisdiction of 35kV ~ 220kV transmission line insulator site contamination measurement conditions and data analysis and puts forward the principle of Sheyang County coastal Lot transmission line insulation configuration, the new transmission insulation configuration principles and operation of transmission equipment and insulation to the implementation of the principles of outside equipment.