We employed a synergistic approach by utilizing in situ etching and phosphating techniques on trimetallic zeolitic imidazolate frameworks (ZIFs) to facilitate the conversion of CoFeNi-ZIFs into CoFeNi/Z-P NC (Nitrogen-doped graphene coating) nanocomposites. Remarkably, the resulting CoFeNi/Z-P NC materials have a large surface area and a lot of pore volume, making their active sites more accessible and makes mass transfer more effective. Additionally, the introduction of Fe and Ni guest metals into the CoP crystal lattice without phase segregation ensures a homogeneous distribution while altering the electrical characteristics. Leveraging these advantages, the CoFeNi/Z-P NC nanocomposites demonstrate a notable enhancement for the OER, 10mA cm-2 is achieved at a low overpotential with a current density of 244mV for alkaline solutions, with a low Tafel slope of 66.2mV dec-1 and has good stability.