Increasing active sites and improving long-term stability are of great significance for electrocatalysts in water splitting. Herein, we report a simple and metal-economize synthesis of NiFe-LDH@Ni-MOF/NF (Nickle iron layered double hydroxide@Nickle metal-organic frameworks/Nickel foam) heterostructures. The NiFe-LDH@Ni-MOF/NF electrocatalyst possesses ultralow oxygen evolution overpotentials of 205, 231, and 248 mV at current densities of 10, 50, and 100 mA cm^–2, respectively, with a small Tafel slope of 43.7 mV dec⁻¹, benefiting from the exposure of edge defects and catalytic active sites, and reduced diffusion pathways for mass and charge transfer, making it one of the best non-noble-metal-based electrocatalysts for oxygen evolution. GRAPHICAL ABSTRACT IMPACT STATEMENT We provide a simple way for synthesizing high-activity and durable LDH/MOF electrocatalysts, without extra metal additions in Ni-MOF in situ synthesis.