Abstract: PLA/PBAT composite films were prepared to explore their properties,and the influence of proportioning and ultraviolet aging time on migration of plasticizer Acetyl Tributyl Citrate (ATBC) from the composite films was studied. 10:90,20:80,30:70 three different proportions of PLA/PBAT composite film were prepared to test the strength,barrier property,crystalline,visible light transmittance performance of the film after ultra violet aging for 72,150,300 h. Using GC-MS based detection methods of ATBC,the influence of different proportion and ultraviolet aging time on ATBC migration was explored. Results showed that the tensile strength and light transmittance had no influence by proportion. The 30:70 (PLA/PBAT) film had the best barrier property and crystalline,and the lowest migration rate of ATBC. Oxygen transmission rate and water vapor transmission rate were 894cc/(m²·d·0.1 MPa) and 520 g/(m²·day),respectively. The crystallinity was 5.99%,and the migration rate of ATBC was 25%. After UV aging,the internal structure of the film would be destroyed,and at the same time,a dense layer would be formed on the surface,which would reduce the mechanical properties and hinder the transfer of ATBC.