The development of highly efficient and bifunctional electrocatalysts is highly desirable for commercializing the rechargeable Zn-air battery. Herein, employing graphitic carbon nitride as carbon precursor, N-doped carbon sheets loaded with Ni3Fe nanoparticles (denoted as Ni3Fe/N-C) have been prepared via a simple pyrolysis strategy. Benefitting from the introduction of triethylene diamine as organic ligand, Ni3Fe nanoparticles with a mean size of 29 nm are dispersed on NC sheets uniformly. As a result, Ni3Fe/N-C exhibits excellent electrocatalytic activity toward both oxygen reduction and evolution reactions (For oxygen reduction reaction, the half-wave potential of Ni3Fe/N-C is 0.81 V; for oxygen evolution reaction, the overpotential at 10 mA cm− 2 is 310 mV). Finally, when used as air electrode in rechargeable Zn-air battery, a high power density of 128 mW cm− 2 and a long cycling life up to 134 h at 10 mA cm− 2 are achieved. Our study thus provides a promising air electrode material for rechargeable Zn-air batteries.