AbstractIn this paper, a novel efficient utilization of lignin‐based nanomagnetic copper (I) is presented as an eco‐friendly recoverable catalyst. We report a simple one‐pot synthesis of magnetic copper chloride (I) composite by using lignin as a reducing agent and heterogenized support. The copper (I) nanocomposite shows high catalytic potential in one‐pot three component click reaction for synthesis of 1,2,3‐triazoles, with excellent turnover efficiency even after 4 cycles in green conditions. The lignin‐copper (I) chloride magnetic nanocomposite catalyst demonstrates highly efficient, stable and recyclable copper (I), and cost effectiveness advantages. The catalyst is easily recovered by an external magnetic field, and therefore, time and energy are saved since there is no filtration or decantation technique. Also, the stable nanomagnetic copper (I) can be handily prepared and applied for large scale operations. Besides, due to totally clear of nanomagnetic copper (I) away from the reaction media, the desired highly pure products can be achieved in excellent yields. High thermal stability of nanomagnetic copper (I) turns its ability to be useable in organic reactions under high temperatures. According to high dispersibility in aqueous solvent, nanomagnetic copper (I) can be utilized as highly efficient catalyst. The prepared composite is characterized by SEM, TEM, XRD, EDX, TGA, VSM and FT‐IR.