Abstract: In recent years，the field of space target localization has developed rapidly by integrating detection technologies such as sensor-network collaboration and multi-mode fusion.Positioning methods based on space-based optical detection are widely used in civil and national defense fields with their unique advantages of good concealment and high measurement accuracy.In order to analyze the localization methods suitable for different types of spatial targets in different scenarios，small space target positioning methods based on space-based optical detection were reviewed.Firstly，the development of space-based optical detection technology，the classification and characteristics of space targets，and the concept of space target localization were introduced.Secondly，the positioning methods based on single satellite or multi-satellites suitable for small and weak spatial targets were analyzed.The joint positioning of heterogeneous sensors proposed in recent years was explained.Besides，the error analysis model of spatial target positioning was established according to the imaging process.The proportion of factors influencing positioning accuracy was analyzed.Finally，the summary and outlook were made based on the existing problems.

Key words: space-based optical detection, spatial moving target, small target, positioning method, positioning accuracy