Porous crystalline metal-organic frameworks (MOFs) are one class of promising electrode materials for CO₂ electroreduction reaction (CO₂RR) by virtue of their large CO₂ adsorption capacities and abundant tunable active sites, but their insulating nature usually leads to low current density. Herein, a two-dimensional (2D) Ni-phthalocyanine-based MOF (NiPc-Ni(NH)₄) that constructed by 2,3,9,10,16,17,23,24-octaaminophthalocyaninato nickel(II) (NiPc-(NH₂)₈) and nickel(II) ions attained high electrical conductivity due to the high overlap of d-π conjugation orbitals between the nickel node and the Ni-phthalocyanine substituted o-phenylenediamine. During CO₂RR, the NiPc-Ni(NH)₄ nanosheets achieved a high CO Faradaic efficiency of 96.4% at −0.7 V and a large CO partial current density of 24.8 mA cm⁻² at −1.1 V, which surpass all the reported two-dimensional MOF electrocatalysts evaluated in H-cell. The control experiments and density functional theory (DFT) calculations suggested that the Ni-N₄ units of the phthalocyanine ring are the catalytic active sites. This work provides a new route to the design of highly efficient porous framework materials for the enhanced electrocatalysis via improving electrical conductivity.