Abstract: With the development of infrared and quantum technologies, up-conversion single-photon detectors in the infrared band have attracted considerable attention and research due to the high sensitivity and fast response speed. However, research on measuring the key parameter, detection efficiency, is currently limited. Correlated photons were generated using the spontaneous parametric down-conversion effect of periodically poled lithium niobate crystals. By combining periodic tuning and temperature tuning, a wide-band mid-infrared correlated photon output ranging from 2.99 µm to 5.01 µm was achieved. The infrared detector detection efficiency measurement device was constructed, and the detection efficiency correction model was used to achieve accurate measurement of detection efficiency. The combined standard uncertainty for the detection efficiency of infrared detectors at the 3.39 µm wavelength band is 2%. The measurement results confirme the feasibility of testing detection efficiency for this type of detector. Theoretically, this method is applicable to other wavelengths.