Abstract: Reinforcing metallic structures by fiber reinforced polymers (FRPs) is an important direction for the application of FRP in the field of civil engineering, which has achieved good development results in the past thirty years. In recent years, more new technologies and related research progresses have emerged. In this regard, a systematic review has been conducted on various new reinforcing/strengthening methods including bonding FRP, using FRP tube/filling, and using prestressed FRP. Experimental research, theoretical analysis, calculation and design methods of the reinforced new components and theoretical models have been analyzed and evaluated. The new mechanical behavior, reinforcing effect, failure mode, key influencing factors, and engineering applicability of the new components under three typical loads of compression, bending and fatigue loading have been discussed. This paper can be used as a reference for experimental research, theoretical analysis, design and engineering applications, and exploration of future research directions of FRP-reinforced metallic structures.