The sluggish charge transfer and poor intrinsic activity are the bottlenecks that hamper the further development of electrocatalysts for hydrogen evolution. A novel core–shell heterostructure of Cu3P@Ni is fabricated, which is composed of Cu3P nanorods covered by metallic Ni. The as-prepared Cu3P@Ni exhibits a durable and superior activity toward hydrogen evolution, with an overpotential of 42 mV to deliver 10 mA·cm−2 and a Tafel slope of 41 mV·dec−1. Charge redistribution is observed after successfully constructing the core–shell heterostructure, leading to the altered electronic structure. The theoretical calculations have manifested that Cu3P@Ni exhibits a zero bandgap and optimized adsorption strength of intermediates, which could give rise to the accelerated charge transfer as well as increased intrinsic activity. This work could shed light on the development of novel electrocatalysts with modulated electronic structure for highly efficient hydrogen evolution.