In this paper, designing, preparation and characterization of a unique nanosized molten salt namely triphenyl(3- sulfopropyl)phosphonium trinitromethanide (TPSPPTNM) was reported. The successful formation of nanosized catalyst was verified by using suitable skills like fourier transform infrared spectroscopy (FT-IR), proton, carbon and phosphor NMR, X-ray diffraction patterns (XRD), field emission scanning electronmicroscopy (FESEM), energy dispersive X-ray analysis (EDX), SEMelementalmapping, high resolution transmission electronmicroscopy (HRTEM), thermogravimetry (TG) and derivative thermogravimetry (DTG) analysis. The catalytic application of the novel molten salt was explored towards the synthesis of pyrano[3,2-c]pyrazole derivatives under mild and green reaction conditions.