Abstract: Azide groups were grafted onto the epoxy resin to improve the wet adhesion strength of the epoxy resin, then the modified epoxy resin was compounded with the epoxy resin 618 in various proportions to prepare underwater antifouling coatings. The adhesion strength, copper ion leakage ratio and marine antifouling performance of the underwater antifouling coatings were investigated.Results showed that the underwater adhesion strength increased first and then decreased with the increase of azide epoxy resin. The copper ion leakage and the submergence showed that the underwater antifouling coatings functioned well in anti-fouling.