The invention provides an SNCR (Selective Non-Catalytic Reduction) denitrification technology test bench. The SNCR denitrification technology test bench comprises a gas distribution and intake system,a plunger flow reactor system and a sampling and testing system, wherein the plunger flow reactor system comprises a furnace tube with an electric heater arranged outside; a fan for air extraction isconnected to the bottom of the furnace tube; the gas distribution and intake system comprises a gas distribution cylinder consisting of two groups of gas cylinders; the first group comprises a nitrogen cylinder, an oxygen cylinder, a carbon dioxide cylinder and a nitric oxide cylinder; the gas outlet of each gas cylinder is connected with a pressure relief valve and a mass flowmeter in sequence,and then connected in parallel with a metering steam generator to the inlet of a mixed gas preheater; the outlet of the mixed gas preheater is connected with the furnace tube through a mixed samplinggun; the second group comprises a nitrogen cylinder and an ammonia cylinder of which the gas outlets are connected with the pressure relief valve and the mass flowmeter in sequence respectively, and then connected with the furnace tube through an ammonia gas sampling gun; and the sampling test system is connected with the furnace tube, and used for measuring the concentration of ammonia in flue gas after denitrification. By simulation of the flue gas with gas distribution, the flue gas composition can be stabilized, and the test conditions are highly repeatable.