PS-11S composite edible film was prepared with potato starch (PS) and soybean globulin (11S) in different proportions (m/m). X-RD， FTIR spectrum， texture， optical properties， permeability， scanning electron microscopy were used to study the interforce， microstructure and mechanical properties of edible film components. The results showed that 11S and PS cross-linked with each other through hydrophobic interaction and hydrogen bond to form a mesh structure and promote the formation of edible film by X-RD and FTIR spectrum analysis. With the increase of 11S content， the mechanical properties of edible film increased first and then decreased. When the ratio of 11S and PS was 2∶15， the elongation at break of edible film reached the maximum 46.69%， the transmittance of water vapor reached the minimum 5.63 mm/m2d·kPa， and the transmittance of oxygen and carbon dioxide were 8.48 g/d·m2 and 12.47 g/d·m2， respectively. When the content of 11S is too high， the porosity of the edible membrane system increases and even cracks occur. Therefore， when the ratio of 11S to PS is 2∶15， the edible film has moderate hardness， compact spatial structure and excellent mechanical properties， which provides a research basis for the preparation of protein-starch composite edible film.