Electrolysis of water to produce hydrogen is a promising green method to achieve sustainable energy supply. A NiCuP foam nickel hydrogen precipitation electrocatalyst was prepared by one-step hydrothermal method. The results show that the electrocatalyst has a good hydrogen reaction activity at 12 h at the nickel?copper ratio of 8:1 and the hydrothermal temperature of 140 ℃. The effect of modifier on the catalytic activity was also investigated. It is indicated that the addition of the modifier NaCl can provide a better ion interaction environment, thus significantly improving the catalytic performance. At a current density of 10 mA/cm2, the overpotential is 108 mV with a Tafel slope of 113 mV/dec (the overpotential change is 113 mV for every 10-fold change in current). The calculations show that the atomic d-p orbital interaction of Ni2P-Cu3P induces an enhancement of the electronic activity at the catalyst interface, thus reducing the activation barrier. Moreover, the addition of NaCl promotes the dissociation of H2O molecules into H ions, thus enhancing the catalytic activity of hydrogen evolution reaction. This work provides a research basis for the research and development of transition metal electrocatalysts.