Energetic polyether binders， as the backbone and matrix of propellants， are the basis to improve the energy levels， mechanical properties， and processing properties of propellants. However， the polar energetic groups in polyethers hinder the movement of molecular chains and reduce the flexibility of polymer chains， leading to a decrease in mechanical properties and restricting the development of energetic solid propellants. Copolymerization modification of energetic polyethers and introduction of flexible structural units to improve flexibility are effective methods to obtain polyethers with diverse structures and adjustable properties. This paper summarizes different types of flexible chain segments introduced into energetic polyethers in recent years， and discusses from the perspectives of main-chain flexible chain segments and side-chain flexible chain segments to explain their effects on the mechanical properties and processing performance of energetic polyether binders. Future design of the flexible chain structure of energetic polyether binders is also discussed， which will provide a direction for the design and development of new types of energetic binders.