Abstract: [Objectives] Compressed air energy storage-hydrogen energy (CAES-HE) coupling systems show outstanding advantages in the field of low-carbon energy transformation, large-scale consumption of renewable energy, and large-scale peak shaving of the power grid. To clarify the current research progress of the CAES-HE coupling system, identify the key scientific and technological issues and the future development directions, this work provides a review of relevant research in this field. [Methods] Firstly, the technical routes and characteristics of different CAES-HE coupling systems were reviewed. Secondly, the key scientific and technological issues in different coupling systems were summarized. Finally, the future development directions of CAES-HE coupling systems were discussed. [Results] Currently, 4 types of CAES-HE coupling systems with different technical routes and characteristics have been proposed. To promote the large-scale development of CAES-HE coupling systems, research and breakthroughs in the following fields are still needed, such as: the new coupling processes development, key common technologies for hydrogen production and storage, hydrogen gas turbine technology, methane reaction mechanism and reactor optimization, etc. [Conclusions] CAES-HE coupling system is one of the most promising directions for energy storage development in the future, and promoting its large-scale development requires joint and continuous research from multiple disciplines and fields.

Key words: compressed air energy storage, liquid air energy storage, hydrogen energy, system integration, energy storage