The invention relates to a low-temperature 
smoke denitration SCR (
silicon controlled 
rectifier) catalyst, which comprises a carrier, a 
manganese oxide, and 
composite oxide of one or more of Ce, Zr, Ti, Co, Fe and Cu, the 
mass content of 
manganese is 0.1-66 percent, and the total 
mass content of the Ce, Zr, Ti, Co, Fe or / and Cu is 0-50 percent; and 
glass fiber and / or kieselguhr is used as the carrier, wherein the 
glass fiber of the carrier is calcined for 2-4 hours at temperature of 400-600 DEG C, then placed in a 
nitric acid, 
sulfuric acid or 
hydrochloric acid solution with 
mass concentration of 5-40 percent for acidizing for 1-8 hours, washed by 
distilled water to be neutered, dried at temperature of 80-120 DEG C, and crushed to have the 
fineness of 20-325 meshes. The catalyst uses the 
glass fiber and the kieselguhr as the carriers, so that the dispersion effect of nanoparticles and specific surface area of the catalyst are increased, the high adsorptive capacity and strong 
heat resistance and 
corrosion resistance capacity are achieved, stronger toxic resistance capacity to 
sulfur dioxide and 
stream contained in the 
smoke is realized, the invention can be used for 10-200 DEG C of low temperature 
smoke denitration, and has strong water resisting and sulphur toxic resisting capacities.