A novel bio‐nanocomposite was developed by incorporating the extracted nanochitosan from shrimp wastes with Schiff base cobalt complex (Chit–Co complex). The phytosynthesis of Chit–Co complex/Ag bio‐nanocomposite was designed utilizing Chit–Co complex at the presence of Ferulago angulate extraction and characterized by AFM, SEM, EDAX, TEM, FT‐IR, and elemental analysis. The radioprotective application of this bio‐nanocomposite on human lymphocyte cells was evaluated using micronucleus (MN) assay. Total antioxidant activities of it were evaluated using FRAP and DPPH assays. Chit–Co complex/Ag bio‐nanocomposite significantly decreased the frequency of micronuclei in human lymphocytes exposed to ionization irradiation (IR). The highest protection was observed at 200 μg/ml. Also, maximum antioxidant activities of bio‐nanocomposite were provided at the same dose. These data exhibit the radioprotective effect of a bio‐nanocomposite based on wastes of living organisms can be an excellent radioprotective agent, which can protect the normal cells of human against the genetic damage by IR.