Abstract: Various instruments such as optical devices and optical coatings used in observation satellites， meteorological satellites and space telescopes must withstood the trial of the space environment and contamination in order to ensure the reliability of spacecraft. To reduce the impact of the space environment and control contamination are the key to solving the problem. Low-temperature optical instruments is a relatively independent system， its thermal design must ensure the coldest sensor chip array to hold the highest temperature in the instrument. Thus， the contaminant is not be adsorbed onto the surface of the key before sensor chip array will be cooled. The best and most basic method of controlling cryogenic instrument contamination is that Optics forever invisible molecules flow from external contamination sources. Installing the heater and contamination control cover at an appropriate position is effective.