With the application and development of wave-absorbing materials in military stealth technology, higher requirements are put forward for their performance. Developing wave-absorbing materials that are “thin, light, wide, and strong” and with excellent environmental adaptability is a critical research topic. The unique multi-principal elements and high-concentration composition of highentropy alloy gives them a natural advantage in terms of being waveabsorbing materials. Its excellent soft magnetic properties, corrosion resistance, oxidation resistance, and other comprehensive properties provide a basis for research into the further development of novel wave-absorbing materials. Optimized absorbing properties of high-entropy alloy absorbing materials can be achieved through host element type and concentration regulation, trace element addition, and compounding with other materials. This paper reviews the research progress of high-entropy alloy absorbing materials, discusses in detail the factors influencing their absorbing properties from the preparation methods of the materials, and finally gives an outlook on the future research directions of high-entropy alloy absorbing materials.