Abstract: This paper conducts an exhaustive review on the exploration history and periodical achievements of domestic and foreign research institutions in the field of flexible wearable upper-limb robots, with focuses on core elements, including system design, sensor configuration, control strategies, and assistance efficacy evaluation of these representative systems. Furthermore, 4 key technologies are systematically summarized, namely the systematic design of wearable robots, precise identification of user intentions, construction of interactive control strategies, and evaluation of assistance efficacy. And, the current technical challenges of flexible wearable upper-limb robots are deeply analyzed, aiming to provide valuable references for subsequent research in this area.