Abstract: An innovative biomass derived keratin composite was fabricated by adopting cellulose nanocrystals (CNC) as reinforcing building block and it was used as adsorbent for dye removal. The resulting CNC/Keratin composite film showed high mechanical strength and satisfying adsorption performance. The properties of CNC/Keratin composite film were characterized. Adsorption behavior of the adsorbent was comprehensively studied. Results showed that the water resistance and tensile properties of CNC/Keratin composite films were better than those of pure keratin membrane. The tensile strength and elongation of pure/keratin composite films were 2.7 MPa and 11%, respectively, and the mass loss in water was 30.5%. When m(CNC)∶m(Keratin) is 5%, the tensile strength and elongation were increased to 15.0 MPa and 12.1%, respectively. When m(CNC)∶m(Keratin) is 10%, the mass loss of CNC/Keratin composite films in water was only 21.1%. The adsorption results showed that the CNC/Keratin film exhibited higher removal efficiency and adsorption capacity for reactive brilliant blue KN-R dye than that of pure keratin film. The removal efficiency and adsorption capacity of 2.5%CNC/Keratin composite film for reactive brilliant blue KN-R dyes reached 78% and 77.57 mg/g at pH 2, respectively. While, the removal efficiency and adsorption capacity of pure keratin film for reactive brilliant blue KN-R dyes were only 55% and 54.52 mg/g at pH 2, respectively. In addition, the adsorption process was in good agreement with Langmuir’s adsorption isotherm model and pseudo-second-order model.