The work aims to study the relationship between the preparation technology and the barrier property of zinc oxide (ZnO) deposited compound films and explore the feasibility of the films applied in the packaging materials, regarding the problems that the ordinary polymer packaging plastics have poor barrier property for water and oxygen and the shelf life of packaged objects is short, etc. ZnO films were prepared via RF magnetron sputtering on PET plastic surface with ZnO as the target material. The influence of RF sputtering power, deposition time and work pressure on the morphology, deposition rate and barrier properties of ZnO compound films was analyzed in detail. When the sputtering power was 150 W, the deposition time was 30 min and the work pressure was 0.8 Pa, the ZnO films were uniform and dense, with the strongest barrier property. The OTR of the film was 1.23 mL/(m2·d), and the WVTR was 0.382 g/(m2·d), which were respectively 49.5 and 17.6 times lower than the original PET film with the same thickness. The sputtering parameters will have a larger influence on the barrier property of the compound films by affecting their morphology, density, deposition rate and deposit thickness, etc.