The invention relates to a thermal insulation optical thin film material. By means of the 6+1 technical scheme, the material is prepared from base material, thermal insulation agent, dispersing agent, fluorescent brightener and anti-aging agent. The thermal insulation agent is divided into a first part with granularity of 1-100 nanometers and a second part with granularity of 101-600 nanometers according to the granularity difference, wherein the weight of the first part accounts for 55-85% of the total weight of the thermal insulation agent. The thermal insulation agent with different granularities is mixed into a plastic formula according to a certain proportion; through the different performances, represented on optics, of the thermal insulation agent with different granularities, an optical protecting material with infrared radiation prevention and thermal insulation functions is successfully prepared. The prepared optical thin film product does not change the high transparency of the plastic product and has the infrared radiation prevention performance; reflecting type thermal insulation agent and absorbing type thermal insulation agent independently act and are evenly dispersed in the PET base material without producing a mirror surface, and secondary light pollution is effectively avoided; meanwhile, the product is long in service life and free of metal oxidation, oxidized black edges and fading.