The present invention relates to a device for measuring livestock barn odor and evaluating the efficiency of a deodorization system, which examines the efficiency of an odor removal system installed in a livestock barn using an inspection unit that detects the efficiency in a single process and allows the deodorization efficiency to be checked on a single screen. The device comprises: a sensing unit installed at a ventilation outlet of the barn, configured to measure the flow rate of exhaust gas discharged through the ventilation outlet; a detection unit installed at the ventilation outlet, configured to direct a portion of the exhaust gas to a treatment unit; a measurement unit configured to evaporate moisture contained in the exhaust gas flowing through the detection unit, remove dust and foreign substances, cool the exhaust gas, measure the flow rate of the exhaust gas, and detect the concentrations of ammonia and hydrogen sulfide in the exhaust gas; and a terminal unit configured to determine whether the barn’s deodorization system is operating normally on the basis of the concentrations of ammonia and hydrogen sulfide detected by the measurement unit and the flow rate of the exhaust gas measured by the sensing unit.