For decades, researchers have been looking for a high-efficiency, low-cost, and environment-friendly photocatalyst for CO2 reduction. In this work, we employed SOCl2 chlorination and EDA passivation to decorate the surface of nanocellulose crystals (NCC), and obtained aminated cellulose crystal NCC-EDA. Next, using coordination and dispersion of amino, hydroxyl, and other functional groups at the NCC-EDA surface, the TiO2 nanoparticles synthesized in-situ from Ti(OBu)(4) were coated by NCC-EDA via a hydrothermal synthesis approach. Subsequently, the composite photocatalyst TiO2/NCC-EDA with various NCC-EDA contents was fabricated. The structure, optical properties, and photocatalytic CO2 reduction performance of the photocatalyst were measured. The results suggest that the NCC-EDA based composite catalyst has highly efficient electron-hole separation and electron transfer as well as excellent CO2 adsorption ability. The TiO2/NCC-EDA exhibits outstanding photocatalytic CO2 to HCOOCH(3 )conversion performance. At reaction time of 6 h, the HCOOCH3 yield is 372.85 mu mol/g cat, which is 4.5 times the yield of pure TiO2 photocatalyst.