To study the influence of long-wave laser on the detection performance of infrared imaging detector, interference experiments on infrared detectors are carried out using a 10.6 μm laser. According to the image acquisition results, with the increase of laser power, the type of interference can be categorized into spot-invariant zone, expansion zone and damage zone, and the corresponding power threshold of each area is 9.35×10^-6, 2.99×10^-4 and 9.35×10^-4 mW/cm², respectively. The differences of spot characteristics under varied laser power are mainly attributed to the difference of laser action mechanism. The interference effect before the damage zone is mainly generated by electronic effect, while the damage zone is dominated by thermal accumulation. The results of this study enrich the understanding of the interference effect of long-wave laser on long-wave infrared imaging system, and provide a basis for the application of long-wave laser interference.