In order to detect the imaging reliability of infrared target with difference wavelength at high & low temperature，black body and IR collimator are adopted to simulate infinite target，IR aiming device is located in high & low temperature and image of IR target is captured by CCD so as to judge the imaging quality of IR aiming device. The designed collimator was with wild-field and its MTF at 20 lp/mm spatial frequency was higher than 0.2 in corresponding focal plane of different wavelength. Meanwhile in order to provide an stable -55 ℃-70 ℃ high & low temperature testing condition rapidly and accurately, a self-adaption fuzzy PID temperature control technology was provided. Adaptive factor was adopted to combine fuzzy inferior and PID controller. By adjusting control parameters on-line, the performance of PID controller was further improved and system control accuracy was raised up. The experimental results show that this method not only improves the dynamic response process but also guarantee no static error. The temperature control precision is ±0.05 ℃.