本发明涉及一种具有漫反射高透过率聚氨酯薄膜的制备方法，在封闭容器中加入多异氰酸酯、抗氧化剂和催化剂，常温搅拌，待催化剂充分溶解后逐滴加入聚硫醚硫醇和聚酯硫醇，滴加甲基丙烯酸‑2‑羟基乙酯和对苯二酚并将温度升至70度进行反应，待NCO全部反应完全并得到聚氨酯预聚物；加入三乙胺，在50度时进行中和反应，滴加二氧化硅水溶胶，加去离子水搅拌乳化，滴加单分散聚合物微球或者无机物微球或者两者的复合微球悬浮液，用旋转蒸发仪脱除丙酮，得漫反射聚氨酯复合乳液；加入催化剂，超声溶解分散，在四氟乙烯模板中浇注成膜，在120度烘箱中干燥8h，得到具有漫反射高透过率聚氨酯薄膜。本申请具有漫反射高透过率等特点。

The invention relates to a preparation method of a polyurethane film with diffuse reflection and high transmittance. Polyisocyanate, an antioxidant and a catalyst are added to a closed container and stirred at the normal temperature, after the catalyst is sufficiently dissolved, polythioether mercaptan and polyester mercaptan are dropwise added, 2-hydroxyethyl methacrylate and hydroquinone are dropwise added, the temperature is increased to 70 DEG C for a reaction, and after NCO completely and fully reacts, a polyurethane prepolymer is obtained; triethylamine is added, a neutralization reaction is performed at the temperature of 50 DEG C, silica hydrosol is dropwise added, deionized water is added, the mixture is stirred and emulsified, monodisperse polymer microspheres, inorganic matter microspheres or composite microsphere suspensions of monodisperse polymer microspheres and inorganic matter microspheres are dropwise added, acetone is removed through a rotary evaporator, and a diffuse reflection polyurethane composite emulsion is obtained; the catalyst is added, ultrasonic dissolution and dispersion are performed, casting film forming is performed in a tetrafluoroethylene template, a film is dried in an oven at 120 DEG C for 8 h, and the polyurethane film with diffuse reflection and high transmittance is obtained. The polyurethane film has the characteristics of diffuse reflection, high transmittance and the like.