Rapid construction of ripple web (RW) is a new construction technology that can be applied to the prestressed concrete (PC) box girder bridge with corrugated steel webs (CSWs). In order to analyse the mechanical behaviour in the construction process when the RW method is applied, the main bridge of Zhao-Jun Yellow River Super Large Bridge was adapted as the engineering background, and a three-dimensional simulation finite element model was established. Thereafter, detailed mechanical analyses were carried out for CSWs, top concrete and bottom concrete, lining concrete, temporary support and other structures in the construction process when the RW method was used. The results reveal the excellent quality of the mechanical properties of the structure, thus indicating the structure’s safety and reliability. This study can provide a reference for similar research and have a positive impact on the further promotion of the RW method for application in the continuous girder bridge with CSWs.