Infrared Search and Track – IRST system as a passive panoramic surveillance device based on infrared features can detect and track air or surface targets. It has many advantages, such as high resolution, strong resistance to electronic interference, good concealment, and strong anti-stealth and so on. Because IRST system and the radar can be complemented by multi-sensor data fusion technology. this paper summarizes the research progress and key technology breakthrough of IRST system in domestic and abroad. Then by analyzing the outstanding advantages of IRST technology for one hand the research direction and application prospect of this technology in industrial and military fields are put forward, for the other hand the conceptual design and engineering research of this technology are summarized and prospected.