Objective The phenomenon of bypass pipe corrosion failure occurs in Bohai Oilfield. Taking Well F in Bohai Oilfield as an example, this paper investigated the corrosion mechanism of bypass pipe to guide the selection of bypass pipe material, and to determine the anticorrosive direction and measures of this oil field. Methods Based on the preliminary analysis of pipe corrosion, using scanning electron microscope, tensile strength test machine, X ray diffraction instrument and so on, physical and chemical performance analysis, metallographic analysis, corrosion product XRD analysis and corrosion product spectrum analysis were carried out on corroded bypass pipe of well F. Results In the aspect of chemical composition, the original chemical composition of the 1#, 2#, 3# bypass pipes met the requirements of Spec 5CT API. In the aspect of mechanical properties, the tensile strength and yield strength of 1# bypass pipe were slightly lower than the standard requirements, and the mechanical properties of the 2#, 3#bypass pipes met the requirements of Spec 5CT API. In the aspect of corrosion products, the corrosion products of the 1#, 2#, 3# bypass pipes were mainly composed of C, O, S, Fe, Ca and Mn. Iron oxide was the main product, followed by sulfide, in which C, Ca, O elements should be derived from environmental media, and a small amount of Ti element might be derived from the surrounding contact metal. In the aspect of compounds produced by corrosion, 1# bypass pipe mainly produced iron oxide, and it contained Ca2Fe2O5 which was inferred to be derived from the formation of sand or ore. 2# bypass pipe mainly produced typical rust components, mainly iron oxide, and a small amount of FeO(OH), which was unstable, and could easily produce iron oxide in the air. Conclusion The corrosion of well F was erosion-corrosion and galvanic corrosion.