Abstract: The traditional wireless power transmission technology mainly focuses on unidirectional power transmission. With the expansion of the application field of wireless power transmission technology, there is an urgent need for bidirectional wireless power transmission (BWPT) technology to realize the energy interaction between wireless charging devices. This paper first briefly describes the basic operating principle of a BWPT system, specifically discusses the main research achievements in terms of typical bidirectional conversion topologies, resonant networks, synchronous control techniques, power control strategies, soft switching operation and application scenarios of BWPT system, and analyses the development status of bidirectional capacitive power transfer system and the key issues that need to be addressed. Finally, prospects for research directions worthy of attention in the future are presented.