Polyimide is widely concerned in the field of engineering polymer materials. The development of a new type of polyimide film material with high temperature resistance and good hydrophobicity is an important breakthrough to promote the engineering application of high-performance polymer materials in electric vehicles and other high-tech fields. In this work, the composite polyimide film was synthesized by a two-step method, and the polyimide film was modified by nano-ZrO2 powder. The structure and morphology of the composite film were characterized by means of XRD, SEM, energy spectrum, infrared spectroscopy, etc. and the thermal stability, hydrophobicity and tensile strength of the composite film were tested. The results showed that the addition of nano-ZrO2 enhanced the interaction between polyimide molecular chains, and the heat resistance of polyimide was significantly improved. The decomposition temperature was increased by 20 ℃, the water contact Angle was increased by 60%, and the hydrophobicity was improved. This work provides a new idea for the development of novel high-performance polyimide polymer materials.