With the soy protein isolated(SPI) and zein as the raw material, through modified the zein by microwave to make the microwave modified blended protein film. Selecting the protein liquid volume ratio of SPI and modified zein, ethanol content, pH of film-forming liquid and water bath temperature as studying factors, the mechanical properties of blended film (breaking strength and fracturing distance) as targets for single factor experiment was studied. And the microstructure, thermal characteristics and FT—IR of the microwave modified blended protein film were also studied, which was obtained by the best ultrasonic film-forming conditions. The results showed that the blended film had the maximal breaking strength (2 900.00 g) and the highest fracturing distance (16.08 mm), with the protein liquid volume ratio of SPI and modified zein 3∶1, the ethanol content 20%, the pH of film-forming liquid 12 and the water bath temperature 80 ℃. The blended film has the better microstructure and thermal stability, the closer intermolecular interactions, and the typical characteristics of secondary structure.