Aiming at the demand of detecting fire in military armored vehicle crew cabin, two solutions for adjusting the detection sensitivity of optical detectors are put forward. It briefly analyzes the principle and classification of optical detection technology, discusses the advantages and limitations of various optical detection technologies. It introduces the selection of optical detector and the influence of temperature on it, then deeply discusses the optical detection temperature adaptation technology in fire extinguishing and explosion suppression systems on certain military vehicle, a software compensation method is used to make up for the burn-in of infrared 1 ms fire threshold, infrared 1 s integrated fire threshold and infrared photosensitive tube, and it is verified repeatedly by high and low temperature test. The experimental results show that the performance of false alarm fully meets the military standard requirements of the optical detector while the temperature is changing from -40 ℃ to 55 ℃.