The hydrothermal method at low temperature (90 degrees C) was used to in situ elaborate TiO2 finished cellulose fabric nanocomposites with different anatase, rutile and brookite compositions. The ratio of different phases of TiO2 was manipulated by subtly altering the hydrochloric acid concentration in the hydrothermal solution. The cellulose fabrics were well preserved under the facile hydrothermal conditions and a homogeneous thin film consisting of TiO2 nanoparticles firmly anchored on the fabric surface even after 30 min of strong ultrasonic processing. The prepared samples were used in photocatalytic reduction of CO2 to CO and CH4 with the highest yields of 194.0 ppm/g and 50.8 ppm/g for CO and CH4, respectively. This study proposes an effective method for in situ and phase controllable synthesis of nanocrystalline TiO2 on flexible cellulose fabrics and provides a reference for the preparation of the novel functional fabric materials.