The preparation of soluble chitosan / cellulose composite film was optimized by quadratic general rotary unitized design, and a quadratic regression equation was established between the film's tensile strength and three factors, namely, soluble chitosan mass fraction concentration, cellulose mass fraction, and glycerin concentration. The influence of the factors on the film's tensile strength was investigated by the equation. Results showed the order of significance that influence the film's tensile strength was cellulose mass fraction, glycerin concentration, and soluble chitosan mass fraction; the optimum preparation conditions of composite film are: soluble chitosan mass fraction 3. 6% , cellulose mass fraction 2. 5% , and glycerin concentration 10% ; under this condition, the tensile strength of the composite film is 0. 801 MPa, elongation at breaking 15. 2% , and softness 288 mN.