In this research, hexamethylene tetraamine propyl silane functionalized nano clinoptilolite (NCP@SiO3PrHMTA) as a novel, green, non-toxic, low cost, heterogeneous, and reusable nanocatalyst was designed, and developed. The structure of the nanocatalyst was fully characterized using various analytical techniques, including; X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS) and thermo gravimetric–differential thermal analysis (TG-DTA). The prepared nanocatalyst has been used as an efficient and recoverable catalyst for the synthesis of aminocoumarin Mannich bases by the three-component reaction of 4-hydroxycoumarin, aniline and aromatic aldehydes. In the presence of this novel nanocatalyst, aminocoumarin Mannich bases were obtained in excellent yields, high purity, and short reaction times under safe and clean conditions.