The utility model discloses an evaluation system for testing the performance of a selective catalytic reduction (SCR) denitration catalyst. The evaluation system comprises a simulated flue gas generation device, an ammonia generation device, a catalytic reactor device, a temperature control device, an unreacted flue gas analysis device and a reacted flue gas analysis device, wherein the simulated flue gas generation device simulates a flue gas generated by an actual boiler, and is connected with the catalytic reactor device through a pipeline which is a before-reaction main pipeline; the unreacted flue gas analysis device and the ammonia generation device are communicated with the before-reaction main pipeline; the catalytic reactor device performs SCR on the flue gas which enters; the temperature control device surrounds the before-reaction main pipeline and the catalytic reactor device; a flue gas outlet pipe of the catalytic reactor device is connected with the reacted flue gas analysis device; and a reacted flue gas enters the reacted flue gas analysis device. By the evaluation system, the actual working condition of a power plant can be simulated, and an SO2/SO3 conversion rate, NH3 escape, denitration efficiency and pressure drop can be tested.