Shear thickening gel (STG) is a promising substrate used for flexible protective materials, which has superior dimensional stability without gel side leakage and delamination when sustaining long-standing time. STG/high-performance fiber flexible composites exhibit high-energy absorption capacity for multivelocity impact. This article reveals the shear thickening mechanism of STG that lays a theoretical foundation for the performance analysis of STG composites. The preparation methods of STG/high-performance fiber flexible composites, including impregnation, hand lay-up, filling, and lamination methods, are compared. The energy absorption principle of STG/high-performance fiber flexible composites on multi-velocity impact and the destruction morphology was analyzed. The coupling effects and functional applications of STG functional composites with nanoparticles, magnetic particles, and conductive particles are summarized. It provides more suitable conditions for designing new multifunctional protective equipment and manufacturing advanced intelligent, protective devices.

Three‐dimensional (3D) structure‐reinforced flexible polymer composites have great potential as personal protective materials. These composites exhibit excellent mechanical properties and failure mechanisms than typical rigid composites because of the complex dynamic reaction processes caused by the 3D structure in response to impact. This paper comprehensively reviews the impact resistance mechanism of 3D structure‐reinforced flexible polymer composites by combining current results with relevant investigations. 3D woven fabric reinforcements and flexible matrix materials of flexible polymer composites systems are presented in this paper. The classification for 3D woven fabric reinforcements is reviewed, as well as the effect of reinforcement structures on the impact resistance of the flexible composites. Furthermore, several flexible matrix are introduced. Several external factors affecting the impact resistance of composites are then discussed. Finally, the impact damage mechanism of 3D structure‐reinforced flexible polymer composites is summarized and analyzed.