Abstract: With the continuous construction of energy storage power stations and the continuous expansion of the electric vehicle market, a large number of retired lithium-ion batteries will be produced in the next few years. If these batteries are not handled properly, it will not only cause a waste of resources, but also cause irreversible pollution to the environment. Therefore, the development of efficient retired battery recycling technology is an important way to promote the sustainable development of lithium-ion batteries and achieve the goal of carbon peaking and carbon neutrality. At present, the main recycling methods of retired batteries include indirect recycling and direct recycling, which has more obvious environmental and economic advantages. The direct regeneration method realizes the recovery of components, the repair of crystal structure and defects through simple steps, so that the spent cathode is transformed into a new cathode with excellent electrochemical performance, which does not need to decompose into separate elements or destroy the original crystal structure. In this paper, the failure mechanism of ternary cathode is summarized. Based on the failure mechanism, the regeneration mechanism and regeneration effect of different direct regeneration methods are analyzed and summarized. Then, the broad development prospect of direct regeneration of waste lithium-ion batteries is discussed from the aspects of economic benefits and environmental problems. Finally, the challenges facing the development of direct regeneration from laboratory scale to practical production applications are discussed, and corresponding insights are provided.