A photocatalytic material for efficient photocatalytic removal of a high-concentration nitrate, and a preparation method and use thereof are disclosed. The preparation method includes the following steps: step 1: preparation of a citrate-stabilized silver nanoparticle; step 2: synthesis and functionalization modification of SiO2 step 3: preparation of Ag/SiO2; and step 4: preparation of an Ag/SiO2@cTiO2 core-shell structure. The photocatalytic material prepared by the present disclosure has high reduction catalytic activity and can quickly remove a high-concentration nitrate and achieve high nitrogen selectivity. In addition, due to protection of a titanium dioxide shell, the photocatalytic material has excellent stability and can remove a high-concentration nitrate in water when the nitrate coexists with a high-concentration chloride ion.