Abstract: The space-based target situational awareness system, as an important means of monitoring the motion status and characteristic measurement of space threat targets, has unique advantages compared to ground situational awareness methods and has become a hot development topic in the world's aerospace field. In the face of the perception demand for accurate recognition and measurement of dim targets, stealth, camouflage and other complex targets in remote space under the interference of space background noise, relying on a single means of space situational awareness is far from meeting the development demand of future space confrontation. Multi sensor data fusion technology can make up for the lack of perception ability between different sensors, give their respective advantages, and form a clearer and more complete multi-dimensional perception description of the situation of space targets. It has obvious advantages in expanding the space-time coverage of target perception information, enhancing target recognition ability and reducing false detection rate. Based on the analysis of the current development status of space target situational awareness capabilities and situational awareness information fusion technology in major aerospace countries.this article summarizes the development status, future progress and trends of relevant technologies and equipment, and provides examples of spatial situational awareness data fusion applications. Finally, it proposes suggestions for the development of China's space situational awareness system, which will contribute to the development of space-based space target situational awareness and multi-source data fusion technology, accelerating the construction of an integrated technology system for spatial situational awareness to provide reference.