Opening agent is used in the production of plastic films, which can effectively improve the opening properties of the film. In this paper, four kinds of silica (SiO₂) opening agents were synthesized by precipitation method, and four kinds of LLDPE/SiO₂ masterbatch were prepared by melt blending with linear low density polyethylene (LLDPE) under the same processing conditions. The results show that the four kinds of opening agents can meet the requirements of anti-sticking and opening performance of LLDPE film, and the dynamic/static friction coefficients are all reduced to less than 0.11 (belonging to high smoothness). After compacting at 50 ℃ and 7 kPa for 24 h, there was no adhesion between the four LLDPE/SiO₂ films, but pure LLDPE films had some adhesion. AFM test shows that there are micro pits near the submicron SiO₂ opening agent particles, which play a key role in reducing negative pressure and van der Waals force, thus reducing the adhesion of LLDPE/SiO₂ films. Based on the test data, a model of anti-sticking opening for LLDPE film is proposed, which is expected to be used to guide the production of opening agents with higher anti-sticking opening efficiency.