Abstract: The present disclosure discloses a core-shell structured NiSe2@NC electrocatalytic material having a general formula of NiSe2@NC. The present disclosure also provides a preparation method and use of the catalytic material. In the present disclosure, hydrazine hydrate is used as a reducing agent, selenium powders are used as a source of selenium, and a metal-organic framework (MOF) is used as a precursor. Selective selenization of mixed-linker MOFs based on mixed ligands is carried out through a hydrothermal reaction. Then, a series of adjustable N-doped carbon-coated NiSe2 nano-octahedrons are prepared through a one-step calcination reaction. By adjusting the types of mixed ligands in the MOF, carbon-coated nickel diselenide composites doped with different pyridinic-N contents can be obtained. Corresponding electrochemical tests prove that, the electrocatalytic activity has a strong correlation with the content of pyridinic-N.