Cholesteric liquid crystal elastomer (CLCE) is a new kind of soft smart material. It combines the unique optical properties of cholesteric liquid crystal (CLC) with the excellent mechanical properties of elastomer. Compared with ordinary CLC, CLCE adds reversible and delay-free mechanical regulation ability, which raises the utilization of stimulus responsiveness of CLC to a new height, and has attracted more and more attention in the fields of information encryption and anti-counterfeiting, soft actuator, mechanical sensing, etc. With the deepening of related research, the preparation method of CLCE is continuously improved, and the material properties are continuously enhanced, various potential applications of CLCE are explored. This paper introduces the basic characteristics, preparation and alignment methods, and different types of external-stimuli responsive behavior of CLCE. Finally, the application prospect of CLCE is prospected.