The oxidative homocoupling reaction of terminal alkynes has attracted much attention due to its important applications in the synthesis of organic compounds, natural products, drugs, supramolecular materials, and π-conjugated oligomers. In this study, the Cu(I)@α-Fe2O3/N-C NSs catalyst was first synthesized and characterized using various techniques, including infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM). The catalyst also exhibits magnetic properties. The activity of the Cu(I)@α-Fe2O3/N-C NSs heterogeneous magnetic catalyst was investigated in the homocoupling reaction of terminal alkynes in the presence of triethylamine as a base and a deep eutectic green solvent (Choline chloride/Urea) for the synthesis of symmetric 1,3-diynes. The homocoupling products were identified using different spectral data (FT-IR, 1H NMR and 13C NMR). The main advantages of this method include the use of inexpensive and readily available materials for catalyst preparation, a clean reaction with high yield, and relatively short reaction times. Furthermore, the catalyst could be easily separated from the reaction mixture using an external magnet, and the recovered catalyst was successfully reused in four consecutive cycles with the coupling product obtained in acceptable yields.