Antifouling zwitterionic materials have extensive applications in the biomedical field. This study designed and successfully synthesized a novel poly(carboxybetaine) diacrylate (PCBDA) via cationic ring-opening polymerization of 2-methyl-2-oxazine, chain modification by the Michael reaction, and chain end transformation to acrylate. The cross-linker was obtained with a tunable molecular weight. Through photopolymerization, poly(carboxybetaine) (PCB) hydrogels with varying solid contents were obtained, and the effects of the solid content on the hydration properties, mechanical properties, and microstructure of the PCB hydrogels were investigated. Furthermore, the non-fouling properties of the PCB hydrogels were compared to those of commercial polyethylene glycol (PEG) hydrogels. Protein adsorption on PCB hydrogels was reduced by more than 60% compared to low-fouling PEG hydrogels. PCB hydrogels exhibit antibacterial adhesion properties similar to those of PEG hydrogels. In cell adhesion experiments, no cell adhesion was observed on the PCB hydrogels, indicating their superior anti-cell adhesion function. This advancement offers a more promising alternative to polyethylene glycol diacrylate (PEGDA) cross-linkers in the design of hydrogels.