In this paper, a new nano-magnetic catalyst has been synthesized by immobilization of ionic liquid triethanolammonium bicarbonate with modified Fe3O4 NPs ([Fe3O4@Si-(CH2)3-TEA] [HCO3]). After, its characterization by different techniques such as FT-IR, XRD, FE-SEM, and EDX, it was used as an efficient catalyst for the knovenegel condensation. The protocol has a number of advantages which is including the ease of purification, recyclable by an external magnet, high yields (85-95% and time (15-50 min), the reusability of the catalyst (at least 5 times without reducing the catalytic activity), its high thermal and chemical stability, and its high selectivity and efficiency.