This study explores the use of covalent organic frameworks (COFs) to enhance the stability and efficiency of perovskite solar cells (PSCs). Specifically, it focuses on the in situ growth of a COF, TpPa-1-COF, on the surface of a metal-organic framework (MOF-808) to form a core-shell MOF@COF nanoparticle. This core-shell structure effectively inhibits the stacking and aggregation of COFs, optimizing the crystallization of large-grained perovskite films and reducing defects. The MOF@COF nanoparticles are shown to improve the power conversion efficiency (PCE) of PSCs to 23.61%, with a superior open-circuit voltage (VOC) of 1.20 V. Additionally, the MOF@COF nanoparticles can chemically fix and adsorb leaked lead ions, reducing lead leakage to less than 5 ppm, which meets the laboratory assessment standards. The study also demonstrates the long-term stability of the PSCs, maintaining approximately 90% of their initial PCE after 2000 hours under various conditions. The findings highlight the potential of MOF@COF nanoparticles in developing stable and eco-friendly PSCs.This study explores the use of covalent organic frameworks (COFs) to enhance the stability and efficiency of perovskite solar cells (PSCs). Specifically, it focuses on the in situ growth of a COF, TpPa-1-COF, on the surface of a metal-organic framework (MOF-808) to form a core-shell MOF@COF nanoparticle. This core-shell structure effectively inhibits the stacking and aggregation of COFs, optimizing the crystallization of large-grained perovskite films and reducing defects. The MOF@COF nanoparticles are shown to improve the power conversion efficiency (PCE) of PSCs to 23.61%, with a superior open-circuit voltage (VOC) of 1.20 V. Additionally, the MOF@COF nanoparticles can chemically fix and adsorb leaked lead ions, reducing lead leakage to less than 5 ppm, which meets the laboratory assessment standards. The study also demonstrates the long-term stability of the PSCs, maintaining approximately 90% of their initial PCE after 2000 hours under various conditions. The findings highlight the potential of MOF@COF nanoparticles in developing stable and eco-friendly PSCs.