To improve the reactive performance of polyethylene film, the fluorination of polyethylene film was investigated. At constant temperature, the modified polyethylene film samples were prepared by changing the pressure parameters of fluorination reaction, and the FTIR and SEM techniques were applied to analyze the surface of polyethylene film to reveal the optimal reaction condition for fluorination of polyethylene membrane. The experimental result shows that with the nitrogen as the protection gas, the progressive fluorination under130 and 220 mPa at 60℃ can achieve carboxylation and fluorination modification on polyethylene film surface, which improves the reaction performance of polyethylene film.