A series of(PDMS-b-PEG) amphiphilic block copolymers were synthesized via a two-step hydrosilylation reaction,and polydimethylsiloxane(PDMS),polyethylene glycol dimethacrylate(PEGDMA), and vinyltriethoxysilane(VTOES)were used as raw materials. Quaternary ammonium salt-functionalized amphiphilic organosilicon anti-fouling coatingswere prepared by mixing the copolymers with 2-methacryloyloxyethyltrimethylammoniumchloride(QAS). The results indicated that both the(PDMS-
b-PEG) block copolymers and QAS-block copolymers exhibited microphase separation on the surface of the coatings. The degree of microphase separation was most pronounced when the molar fraction of PEGDMAmonomer was 60%,and it became more prominent after introducing the QAS functional group. Additionally,with an increase in the hydrophilic segment,the anti-protein effect was improved.The optimal antifouling performance was achieved when the molar fraction of PEGDMA monomerwas 60% and the mass fraction of QAS was 3%. Furthermore,the coating demonstrated excellentmarine antifouling properties based on a 90-day seawater immersion test.