Transition metal dichalcogenides have been the most attractive two-dimensional layered materials for electrocatalytic hydrogen evolution due to their unique structure and multi-phase electronic states. However, the enhancement of the WSe2 electrocatalytic hydrogen evolution reaction (HER) performance by bimetal co-doping has been rarely reported. Herein, the NiMo-WSe2 catalyst has been synthesized by a one-step hydrothermal reaction, with lower overpotentials of 177 and 188 mV at a current density of 10 mA cm-2 in 0.5 M H2SO4 and 1 M KOH, respectively. The large specific surface area and thinner edge morphology provide more active sites for hydrogen production, thereby significantly improving the charge transfer kinetics. Density functional theory calculation results show that under acidic conditions the ΔGH* values of NiMo-WSe2 with different structures and hydrogen adsorption sites are also different, when the hydrogen adsorption site was located at the top of the Se-Ni bond, the meta NiMo-WSe2 has a ΔGH* value (-0.04 eV) that is closest to 0. Meanwhile, NiMo-WSe2 (meta) also has a minimum of ΔGH* under alkaline conditions. DOS confirmed that Ni doping has a large impact on the electronic states at the WSe2 Fermi level, while NiMo co-doping greatly reduces the potential energy barrier of the HER reaction, jointly increasing the current density, and thus improving the HER performance.