The prevalence of nanoplastics in water has led to significant environmental and health concerns, yet effective and scalable strategies for mitigating this contamination remain limited. Here, we report a straightforward, efficient, and scalable approach to degrade nanoplastics in water using enzyme-loaded hydrogel granules with an interconnected porous structure and adjustable properties. These porous hydrogels were synthesized via a polymerization-induced phase separation method, allowing easy scaling-up. Our results show that enzyme-functionalized porous hydrogels slightly outperform free cutinase in nanoplastic degradation. Furthermore, immobilized enzymes exhibited enhanced stability under harsh conditions, achieving a 104.1 % higher PET removal rate at pH 5 than free cutinase. Notably, the immobilized enzyme retained 39.9 % of its initial degradation activity after five cycles, demonstrating good reuse stability. This method offers a promising and practical solution for using enzymes to address nanoplastic pollution in aquatic environments.