As a key component of the future aerospace vehicle power system, the condition monitoring and performance evaluation of the structure of composite tanks is one of the key issues to ensure the safe operation of spacecraft. Acoustic emission is a new dynamic non-destructive testing / monitoring technique that effectively monitors the structural performance of composite tanks. This paper takes composite tanks as the background. Firstly, the failure modes and common health assessment techniques of composite tanks are introduced. Secondly, the basic principles of acoustic emission detection technology are introduced, and the current status of research on the application of acoustic emission technology to the damage characteristics of composite tanks is reviewed. Finally, the development trends and challenges of acoustic emission monitoring of structural health of composite tanks are discussed.