TiO2–SiO2 thin film was prepared by sol‐gel method and coated on the aramid fabric to prepare functional textiles. The aramid fabric was dipped and withdrawn in TiO2–SiO2 gel and hydrothermal crystallization at 80°C, then its UV protection functionality was evaluated. The crystalline phase and the surface morphology of TiO2–SiO2 thin film were characterized using SEM, XRD, and AFM respectively. SEM showed hydrothermal crystallization led to a homogeneous dispersion of anatase nonocrystal in TiO2–SiO2 film, and XRD suggested the mean particle size of the formed anatase TiO2 was less than 30 nm. AFM indicated that hydrothermal treatment enhanced the crystallization of TiO2. UV protection analysis suggested that the hydrothermally treated coated textile had a better screening property in comparison with TiO2–SiO2 gel and native aramid fabric. Microsc. Res. Tech. 78:918–925, 2015. © 2015 Wiley Periodicals, Inc.