The invention provides a low-temperature SCR catalyst based on active coke-loaded active components and a preparation method thereof. The catalyst is suitable for selective catalytic reduction of nitrogen oxides under low temperature conditions. By loading Mn and Ce composite oxides on active coke particles with high specific surface and mechanical strength, the temperature of SCR reaction can be reduced, the adsorption capacity and mechanical anti-wear ability of the catalyst can be improved, and the overall sulfation resistance of the catalyst can be improved. and regeneration capacity. The preparation method of the invention has simple steps, ingenious process design, and is convenient for realizing industrialized production. The catalyst of the invention uses active coke particles as a carrier, and Mn and Ce composite oxides are loaded on the carrier. The carrier of the catalyst can also be loaded with oxides of modifying elements, the modifying elements are: Fe, Zr, Si, Ti, V, Mo, W, Cr, Au, Ag, Pt, Pd, Rh, Co elements one or several.