Multi-field uniform selective catalytic reduction (SCR) flue gas denitration apparatus

The invention provides a multi-field uniform SCR flue gas denitration apparatus which can effectively prevent large granule from entering into the interior of a flue, allows a catalyst and related equipment to work normally and enables flue length at an inlet of a denitration reactor to be effectively shortened, small arrangement difficulty and resistance loss to be realized and economy and reliability of a denitration system to be improved. The apparatus comprises a boiler, a coal economizer, a denitration reactor inlet flue and the denitration reactor, wherein, the boiler is connected with the coal economizer, and the coal economizer is connected with the denitration reactor through the denitration reactor inlet flue; the invention is characterized in that: the front part of the denitration reactor inlet flue is of an ascending structure, a large granule intercepting sieve is installed at an inlet end of the front part of the denitration reactor inlet flue, and the outer rim of the large granule intercepting sieve is tightly connected with the inner wall of the denitration reactor inlet flue; an ash bucket is arranged below the large granule intercepting sieve.