Abstract: In-orbit spacecraft are frequently subjected to extreme multi-physical field coupling effects, such as mechanical damage and radiation interference from the space environment, which can cause damage (eg. interface delamination and matrix cracking) to their conventional rigid structures. This leads to a degradation of critical load-bearing capacity and an increase in operational safety risks. To achieve long-term reliable operation of spacecraft, it is urgent to develop flexible intelligent structural systems that integrate monitoring, sensing, and self-healing capabilities. This paper focuses on the key sensing units in flexible structures for spacecraft, specifically self-healing flexible sensors, and discusses their two design mechanisms: dynamic covalent bonds and dynamic non-covalent bonds. In combination with the challenges posed by the actual operational environment of spacecraft, the paper discusses future development trends of self-healing flexible sensors, including enhanced strength and toughness, high anti-interference capabilities, and multi-sensing capabilities.