The semi-hydrogenation of terminalalkynes is successfully achieved with NaBH4 catalyzed by recyclable palladium nanowires (PdNWs) under ambient conditions. With only 0.32 mol % of catalyst loading, the reaction gives the hydrogenated products with up to 98 % overall yields, in which 97 % are semi-hydrogenated products. The method expands the application of metal nanomaterials in organic syntheses