Thrombosis and infection are two major complications associated with central venous catheters (CVCs), which significantly contribute to morbidity and mortality. Antifouling coating strategies currently represent an efficient approach for addressing such complications. However, existing antifouling coatings have limitations in terms of both duration and effectiveness. Herein, we propose a durable zwitterionic polymer armor for catheters. This armor is realized by pre-coating with a robust phenol-polyamine film inspired by insect sclerotization, followed by grafting of poly-2-methacryloyloxyethyl phosphorylcholine (pMPC) via radical polymerization. The resulting pMPC coating armor exhibits super-hydrophilicity, thereby forming a highly hydrated shell that effectively prevents bacterial adhesion and inhibits the adsorption and activation of fibrinogen and platelets . In practical applications, the armored catheters significantly reduced inflammation and prevented biofilm formation in a rat subcutaneous infection model, as well as inhibited thrombus formation in a rabbit jugular vein model. Overall, our robust zwitterionic polymer coating presents a promising solution for reducing infections and thrombosis associated with vascular catheters.