Soy protein isolate (SPI) packaging films were prepared with SPI as raw material through regulating the proportion of SPI and glycerol. The appearances of the films were observed for white degree, flexibility. Their mechanical property, moisture barrier property and oxygen barrier property data were measured and compared. The results showed that the main factors influencing the SPI film performance are SPI dosage, the ratio of SPI to glycerol, and drying condition; the SPI film can acquire the best performance when SPI concentration to 5.66%, SPI: glycerol to 6∶1.5, and the drying method of air combined with oven drying at pH 9.