The coordinated development of new energy vehicles and the energy storage industry has become inevitable to reduce carbon emissions. The cathode material is the key material that determines the energy density and cost of a power battery, while the currently developed and applied cathode material can not meet the requirements of high specific capacity, low cost, safety and good stability. High-entropy material is a new type of single-phase material composed of multiple principal elements in equimolar or near-equimolar ratios. The interaction between multiple elements can play an important role in improving the comprehensive properties of the material, which is expected to solve the limitations of battery materials in practical applications. Based on this, this review provides a comprehensive overview of the current development status and modification strategies of power batteries (lithium-ion battery and sodium-ion battery), proposes a high-entropy design strategy, and analyzes the structure-activity relationship between the high-entropy effect and battery performance. Finally, future research topics of high-entropy cathode materials are proposed, including computational guide design, specific synthesis methods, high-entropy electrochemistry and high-throughput databases. This review aims to provide practical guidance for the development of high-entropy cathode materials for next-generation power batteries.