WPI-NaCas-GLY composite protein films were modified by pullulan (PUL) addition with different ratios. The mechanical properties, optical properties, oxygen permeability, water permeability and water solubility of protein-based films were investigated. The experimental results showed that compared with the WPI-NaCas-GLY composite protein film, the tensile strength of the PUL- protein-based film decreased, while the elongation at break increased to 208.26%, the light transmittance increased by 11%, and the haze decreased by 6%. Furthermore, the oxygen transmission rate has gone down to 1/6, and the water solubility changed slightly. When the amount of added PUL reached 66%，the water vapor transmission coefficient of the film decreased to 2.57×10-13 g cm/(cm2 s Pa), and the oxygen transmission rate dropped to 0.16 cm3/(m2 d). It was inferred that PUL had the capacity of improving the mechanical properties, optical properties and barrier properties of protein-based films.