Through the field research and analysis of the service environment characteristics and equipment corrosion in the substation in the marine environment,the research found that the coastal environment substation equipment corrosion is more serious,and mainly occurs in the equipment connection gap,bolts and other shaped position,the substation equipment structural characteristics is the main factor affecting the corrosion situation.Through the test analysis and research of substation equipment sealing connection gap width on corrosion,found that equipment sealing connection gap width of(1~2)mm,the corrosion degree of the material is the lightest;based on the research and study put forward to improve the corrosion resistance of the equipment of the structural design measures to help improve the corrosion resistance of coastal substation equipment.