Bolt corrosion is one of the important factors threatening the long-term security and stable operation of bridges. In order to determine the reason of bolt corrosion, according to the statistical analysis results of the spatial and temporal distribution and type distribution of 81 high-strength bolts which were found in Chaotianmen Bridge from 2013 to 2018, 6 representative samples were selected. The relationship between failure of high-strength bolt and environmental corrosion was discussed, corrosion test of high strength bolt under simulated humid climate in Chongqing were carried out. The chemical composition and micro morphology of the corrosion products were analyzed by using Q8 direct reading spectrometer, SEM, EDS, and XRD. The chemical composition analysis results show that both the elements of the failed bolts’ core and the new bolts’ core are Fe, C, Mn and Si, which are uniformly distributed, while elements of the corrosion products on the surface of fracture failed bolt sand the high strength bolt under simulated corrosion environment are various and serious segregation, and are mainly of oxygen and Fe. Apart from rust, the EDS results show that there were S, Cl, Al, Si, K and other elements in the corrosion products, and the XRD results show that there are iron sulfide, oxides of manganese, silicon and other oxides. It is speculated that the fracture failure of high-strength bolts is related to atmospheric corrosion (acid rain), industrial dust, road dust and other environmental corrosion.