Cellulase bound magnetic nanoparticles was used as nanobiocatalyst for the hydrolysis of Sesbania aculeate biomass in the present study. The characteristic peak at 1624 cm<SUP>-1</SUP> in FT-IR spectrum confirmed the presence of cellulase on MNP. The particle size of the nanobiocatalyst was found in the range of 90-100 nm and it was structurally found to be cubic in nature. The paramagnetic behavior of nanobiocatalyst was confirmed by VSM analysis. The optimal parameters are 1.5% (w/v) of nanobiocatalyst concentration, biomass concentration of 4% (w/v) and temperature at 30 <SUP>o</SUP>C. The maximum bioethanol yield of 5.31 g/l was obtained using Sesbania aculeate biomass hydrolysate under optimal conditions. The produced bioethanol was confirmed by GC-MS analysis. Reusability study was analyzed and proved that the nanobiocatalyst was efficient for the feasible production of bioethanol.