Dextrin is a water soluble polysaccharide obtained by hydrolysis of starch or glycogen. This low molecular weight biopolymer with valuable properties such as biodegradability, natural origins, good availability and high reactivity can be an appropriate substance to fabricate the environmentally friendly catalysts. The magnetized dextrin was prepared via facile co- precipitation procedure of iron salts in the presences of dextrin under alkaline condition. Then, it was characterized by different conventional analyses. Eventually, the catalytic application of obtained nanocatalyst was evaluated for the synthesis dihydropyrano[2,3-c]pyrazole derivatives through multicomponent reaction of hydrazine hydrate, ethyl acetoacetate, aromatic aldehydes and malononitrile. Utilizing biocompatible nanocatalyst, simple procedure, short reaction times, and catalyst reusability after four consecutive runs with negligible decrease in catalytic efficiency are some merits of presented method.