The work aims to prepare edible packaging materials with edible soy protein isolate (SPI) as film substrate. The soy protein isolate film was prepared by solution-casting method. The effects of SPI amount, ratio of SPI to glycerin and solution pH on the mechanical properties, light transmission and barrier properties of SPI film were studied. The optimal preparation conditions were SPI amount of 6%, solution pH of 9 and SPI to glycerol for 2.5. The properties of SPI film under the above conditions were the best. The tensile strength was 10.7 MPa, the break elongation was 242.9%, the light transmission rate was 86.1%, the haze was 4.8%, the water vapor permeability rate was 1684.3 g/(m2∙24 h), and the oxygen permeability rate was 4.28 cm3/(m2∙24 h∙0.1 MPa). The SPI film has the advantages of higher mechanical properties, better light transmission and higher oxygen resistance and can be used in product packaging.