The development of cost-effective electrocatalysts to produce high-purity hydrogen by electrochemical water splitting is critical to addressing resource and environmental problems. Theoretically, NiW materials are considered to be an excellent HER electrocatalyst. However, current NiW catalysts for HER are not satisfactory. Herein, the NiW solid solution with twin boundaries is successfully fabricated by facile electrodeposition on copper sheet. As compared with Ni, the NiW-0.6A catalyst shows enhanced HER activity in 1 M KOH with the overpotential of 98 mV at 10 mA/cm². Besides, NiW-0.6A exhibits excellent stability for 100 h at 20 mA/cm². The excellent HER performance of NiW-0.6A may be attributed to the intrinsic catalytic activity and the defective twin boundaries exposing many active sites. This work could provide feasible suggestions for the design of efficient and high-performance NiW electrocatalysts for HER process..