In order to investigate the overall stability behavior of Q460 high strength steel welded I-section two-span continuous beam and develop the design method of such beams in codes, a finite element model considering residual stress was established by using ANSYS finite element program, and the model was verified on the basis of experimental data of Q345 steel two-span continuous beam. With the finite element model verified by experiment, the overall stability behaviors were investigated by changing the residual stress distribution model, span ratio, steel strength, section height-width ratio, and loading ratio. According to the finite element analysis results, the formula of elastic critical moment was regressed. Furthermore, the elastic critical moments obtained through the above formula were substituted into the overall stability factor formula in the specification for design of high strength steel structures (JGJ/T 483-2020)to obtain overall stability factor, which was compared with that obtained by finite element analysis. The comparison results indicate that the above method is suitable for the overall stability design of Q460 high strength steel two-span continuous beam.