Abstract: Fiber reinforced polymer (FRP) composite has great potential in infrastructure construction due to the advantages of light weight and high strength, corrosion resistance and high economic benefit. However, the performance of FRP composite will decrease by more than 50% after long-term service in complex environment, which limits its application in engineering. In the paper, the enhancement methods of different FRP composites components are reviewed. The evolution law of FRP composites on long-term properties under thermal oxygen, ultraviolet and corrosive media environment are revealed, and the deterioration mechanism of FRP composites in complex environment is elucidated by the analysis of chemical structure and microstructure. In addition, the long-term performance prediction model of FRP composites under complex environments is summarized, which can provide theoretical basis for ensuring the long-term performance of FRP composites in complex environment and promote its application in practical engineering.