Abstract: The effect of different plasticizers on the properties of gelatin films were studied. The modified gelatin films were prepared by casting method.Meanwhile, its mechanical properties, thermal stability and optical properties were characterized.The results showed that when the mass concentration of ethylene glycol, glycerol and sorbitol was 12.5%. The elongation at break reached the maximum 113.00%, 145.33% and 120.63%, respectively. With the addition of plasticizer ethylene glycol, glycerol, sorbitol, the thermal shrinkage of the modified gelatin film increased by 1.70%, 2.84% and 1.94%, respectively.At the center of visible light 600 nm, the light transmittance of modified gelatin films by ethylene glycol, glycerol and sorbitol increased by 8.8%, 11.9% and 8.3%, respectively.The result shows that plasticizers can optimize the performance of gelatin film, and it also can be applied to the actual production.