AbstractPolyethylene terephthalate (PET) is a new type of fiber‐reinforced polymer (FRP) composite material, which has the characteristics of high performance, high toughness, high tensile fracture load, low elongation, low creep, no rust, and safety in use. The good performance of PET can significantly improve the mechanical properties of its components. A total of six reinforced concrete (RC) beams were produced in the test, one of which was a comparison beam, and the other five were reinforced with PET. In the test, the PET reinforcement spacing, number of reinforcement layers, and laying method were used as control variables, and an experimental study on the normal section bending performance of the specimen was performed. The test analyses the failure characteristics, crack width, bearing capacity, and deflection of the specimens under different reinforcement conditions. The test results showed that PET reinforcement can effectively inhibit the occurrence and development of cracks in RC beams and improve the ultimate bearing capacity and ductility of the components. The smaller the PET reinforcement spacing, the higher the ultimate bearing capacity; the greater the number of PET layers, the better the ductility of the specimen. Additionally, the economy, environmental protection, and portability of PET are of great significance for its application in practical engineering reinforcement.