Girder bridges with corrugated steel webs (CSWs) exhibit critical shear regions proximate to supports, where the CSWs are subjected to peak shear forces and bending moments potentially inducing shear buckling. This study explores the shear behavior within critical regions experiencing hogging bending moments, where the accordion effect of CSWs dramatically exacerbates shear deformation. However, due to the substantially reduced shear stiffness of CSWs relative to concrete slabs and crossbeams, the shear deformation of CSWs is constrained, causing additional shear forces to form within them. The traditional basic shear method proves inadequate in predicting shear stress within CSWs for it omits these additional shear forces. The study introduces an enhanced formula to precisely assess shear stresses within CSWs, particularly in hogging moment regions of girders, considering the additional shear force induced by CSWs' shear deformation. A strong correlation between the additional shear forces and the geometric characteristics of CSWs has been identified through theoretical analysis. Accordingly, the study systematically investigates the impact of various parameters on the additional shear force through finite element parametric analysis. Comparative analysis demonstrates that the CSWs’ thickness, the height-to-span ratio, and the boundary constraint conditions of girders significantly impact additional shear forces, thereby affecting the shear transfer efficiency within the cross-section of the girder.