The work aims to modify polyethylene (PE) by blending poly adipate butyl terephthalate with high moisture permeability (PBAT), to improve the properties of polyethylene (PE) such as poor moisture permeability and low gas selective transmission ratio. PE/PBAT film was prepared by tape casting blending method with PE as the main component and PBAT with mass fraction of 10%, 20% and 30%. The thermal properties, mechanical properties, gas permeability and moisture permeability of the film were tested. Then, the film was used to package mini cucumber to study the preservation effect. The addition of PBAT improved the mechanical properties, gas permeability and moisture permeability of PE. Compared with PE, the addition of 30% PBAT increased the permeability coefficient of H2O by 2.42 times. The permeability ratio of CO2/O2 increased from 3.3 to 4.4. During the whole storage process of mini cucumber, the Vc content decreased most slowly, and the sensory quality kept well. Mini cucumber had good commercial value and edible value within 38 days of storage. The addition of PBAT improves the properties of PE and increases the storage time of mini cucumber, which has a better prospect of use.