providing a mortar-producing material that includes a fine aggregate and cement, a reactant mixture that includes a zinc source and urea, and a microorganism-containing mixture that includes water and a urease-producing microorganism;

subjecting the microorganism-containing mixture and the reactant mixture to microbial induced precipitation in the mortar-producing material, so as to obtain zinc carbonate crystal-containing mortar;

subjecting the zinc carbonate crystal-containing mortar to a curing process, so that the zinc carbonate crystal-containing mortar undergoes hydration to form cured mortar; and

subjecting the cured mortar to hydrothermal synthesis, so that zinc carbonate crystals in the cured mortar are converted to nano zinc oxide crystals, so as to obtain the photocatalytic mortar containing the nano zinc oxide crystals.