<p>Developing transition metal-based catalysts with high activity and long-term stability has garnered extensive attention for hydrogen evolution reaction (HER). Here, a Co(OH)F nanorod catalyst with a novel CoP/Co(OH)F heterostructure is developed through a simple hydrothermal method and subsequent phosphorization. Notably, the CoP/Co(OH)F shows excellent HER performance, including a low overpotential of 83 mV at 10 mA/cm² and a Tafel slope of 43 mV/dec. Moreover, it also displays outstanding stability for 400 h at a current density of 50 mA/cm². Further analysis reveals that the construction of CoP and Co(OH)F heterojunction interface promotes the electron transfer and further optimizes the adsorption energy of reaction intermediates during HER process. This work provides a new insight to design and construct high-performance heterostructure catalysts for HER.</p>