In this project, the new catalyst copper defines as Fe3O4@Pectin@(CH2)3-Acetamide-Cu(II) was successfully manufactured and fully characterized by different techniques, including FT-IR, XRD, TEM, FESEM, EDX, VSM, and ICP analysis. All results showed that copper was successfully supported on the polymer‐coated magnetic nanoparticles. One of the most important properties of a catalyst is the ability to be prepared from simple materials such as pectin that’s a biopolymer that is widely found in nature. The catalytic activity of Fe3O4@Pectin@(CH2)3-Acetamide-Cu(II) was examined in a classical, one pot, and the three-component reaction of terminal alkynes, alkyl halides, and sodium azide in water and observed, proceeding smoothly and completed in good yields and high regioselectivity. The critical potential interests of the present method include high yields, recyclability of catalyst, easy workup, using an eco-friendly solvent, and the ability to sustain a variety of functional groups, which give economical as well as ecological rewards. The capability of the nanocomposite was compared with previous works, and the nanocomposite was found more efficient, economical, and reproducible. Also, the catalyst can be easily removed from the reaction solution using an external magnet and reused for five runs without reduction in catalyst activity.