In order to develop optical films that can be applied to window films and high-brightness films, self-produced A masterbatch, B masterbatch and film-grade polyester were used to prepare biaxially oriented polyester (BOPET) films by extrusion casting machine and tensile test machine. The microstructure, roughness, optical properties, friction coefficient and mechanical properties of BOPET films were studied by polarizing microscope, line roughness meter, non-contact 3D surface profiler, transmission fog shadowgraph, gloss meter, friction coefficient meter and material tensile machine. The results show that the opening agent is a spherical structure, the size is in the submicron level, showing a monodisperse state. When the content of the opening agent (B masterbatch) is 0.012 5%, the roughness of the film surface R _a \le23 μm, S _a \le17 μm, haze, transmittance, clarity, gloss can reach 0.88%, 90.8%, 99.6% and 136 GU, respectively. The static friction coefficient/dynamic friction coefficient is 0.36/0.30. The anti-bonding effect is good and the mechanical properties are excellent. The prepared BOPET film is a kind of low fog and high definition BOPET film with good comprehensive properties.