The invention discloses an arrangement structure of flue type urea direct-ejection pyrolysis nozzles. The arrangement structure comprises a plurality of nozzles, wherein inlets of the nozzles are all connected with a urea solution input pipeline and a compressed air input pipeline; a first valve is arranged on the urea solution input pipeline; a second valve is arranged on the compressed air input pipeline; the cross section of a flue is divided into a plurality of zones; one zone corresponds to one nozzle; and the nozzles are positioned in central positions of the corresponding zones. By adopting the arrangement structure, the flow of a urea solution of the nozzles and the pressure of compressed air can be adjusted for different zones, and the problem that NOx is not uniformly distributed in fume can be solved.