Abstract: ‍ ‍Building a space-air-ground integrated network has become a national demand to achieve ubiquitous connectivity in all time and space. Multi-target tracking based on cross domain collaborative systems under the space-air-ground integrated network is important， having great application value in both military and civilian fields. This paper elaborates on the research progress of multi-target tracking methods in the context of a space-air-ground integrated network. First， the research background and significance of cross domain collaborative multi-target tracking for space-air-ground integration are introduced. Second， representative research methods are reviewed from three aspects： visual-based， model-based， and multi-modal fusion-based multi-target tracking. In terms of vision-based multi-target tracking algorithms， single camera and cross camera fusion multi-target tracking are introduced. Regarding model-based multi-target tracking， we first introduce the single-sensor multi-target tracking method and its improvement in a variety of complex scenarios， and then introduce the multi-sensor fusion method. In terms of target tracking based on multimodal information fusion， after introducing the multi-sensor spatiotemporal registration methods and representative multimodal information fusion methods， the main algorithms of multi-target tracking based on multimodal fusion are summarized. Finally， the existing problems and future development directions in the field of multi-target tracking are discussed. Both visual- and model-based multi-target tracking methods have numerous problems that need to be solved， and the combination of the two methods is worthy of in-depth research. When facing complex interference， multi-target tracking based on multi-sensor information fusion has become the mainstream development direction owing to its ability to achieve complementary information. In addition， cross-domain collaborative systems， owing to their ability to utilize more resources and information， have great application potential in multi-target tracking problem research. Moreover， the issues of communication security and lightweight multi-target tracking models are also research-worthy. This paper is expected to be of interest to researchers engaged in theoretical and technical research related to target tracking and integrated collaborative control of space-air-ground systems.