Numerous studies have focused on efficient CO2 photoreduction on short notice. However, more hours of efficient and selective CO2 and pure water photoconversion without precious metals or sacrificing reagents should be emphasized. Herein, a multilayer (SrTiO3/Ce:CaF2/CuNi/Ce:CaF2/TiN) is utilized with a high selectivity of 87 % for healable photocatalytic CO2 and pure water conversion without sacrificial reagents and the longest service life for the Cu nanolayers, to the best of our knowledge. Meanwhile, the photocatalytic activity, optical absorption, and charge separation ability of SrTiO3/Ce:CaF2/CuNi/Ce:CaF2/TiN can be recovered after regeneration. The deactivation and healable mechanism are illuminated that the adsorption of CO2 molecules at the photocatalyst surface is changed from M-CO2 to MO-CO2, due to the oxidation of active sites, resulting in the deactivation of CO2 reduction. The Ce:CaF2 nanolayers can accommodate oxygen atoms effectively to heal the photocatalyst. The article proposes a feasible way for commercial CO2 and pure water photoconversion.