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.