This study presents a novel approach to enhance the stability and efficiency of perovskite solar cells (PSCs) by using multifunctional MOF@COF nanoparticles. The MOF@COF nanoparticles are constructed by in situ homogeneous growth of a covalent organic framework (COF) on the surface of a metal–organic framework (MOF-808), forming a core–shell structure. This structure effectively inhibits COF stacking and aggregation, leading to improved crystallinity of perovskite films and reduced lead leakage. The MOF@COF nanoparticles facilitate the efficient transport of charges and the elimination of defects in the perovskite films, resulting in a PSC with a power conversion efficiency (PCE) of 23.61% and an open circuit voltage (Voc) of 1.20 V. The MOF@COF also acts as a trap for leaked lead ions, significantly reducing lead leakage to less than 5 ppm, meeting the requirements of the Resource Conservation and Recovery Act Regulation. The study demonstrates that the MOF@COF nanoparticles can effectively improve the long-term stability of PSCs, maintaining approximately 90% of the original PCE after 2000 hours of operation under ambient conditions. Additionally, the MOF@COF nanoparticles exhibit excellent light absorption properties, enhancing the incident photon-to-electron conversion efficiency (IPCE) and contributing to the overall performance of PSCs. The results indicate that the MOF@COF nanoparticles play a crucial role in mitigating lead leakage and improving the stability of PSCs, making them promising candidates for the development of stable and eco-friendly PSCs.This study presents a novel approach to enhance the stability and efficiency of perovskite solar cells (PSCs) by using multifunctional MOF@COF nanoparticles. The MOF@COF nanoparticles are constructed by in situ homogeneous growth of a covalent organic framework (COF) on the surface of a metal–organic framework (MOF-808), forming a core–shell structure. This structure effectively inhibits COF stacking and aggregation, leading to improved crystallinity of perovskite films and reduced lead leakage. The MOF@COF nanoparticles facilitate the efficient transport of charges and the elimination of defects in the perovskite films, resulting in a PSC with a power conversion efficiency (PCE) of 23.61% and an open circuit voltage (Voc) of 1.20 V. The MOF@COF also acts as a trap for leaked lead ions, significantly reducing lead leakage to less than 5 ppm, meeting the requirements of the Resource Conservation and Recovery Act Regulation. The study demonstrates that the MOF@COF nanoparticles can effectively improve the long-term stability of PSCs, maintaining approximately 90% of the original PCE after 2000 hours of operation under ambient conditions. Additionally, the MOF@COF nanoparticles exhibit excellent light absorption properties, enhancing the incident photon-to-electron conversion efficiency (IPCE) and contributing to the overall performance of PSCs. The results indicate that the MOF@COF nanoparticles play a crucial role in mitigating lead leakage and improving the stability of PSCs, making them promising candidates for the development of stable and eco-friendly PSCs.