To rationally select economical and efficient construction methods for super-large section tunnels under bedding-plane biased pressure while ensuring safety, this study investigates the optimization of construction methods and support systems based on the Chongqing Jinshan Tunnel Guobo Station project through numerical calculations and field monitoring. The results show that both the horizontal displacement on the bedding-dip side and the stress of the support structures are significantly greater than those on the opposite side, with the most pronounced stress heterogeneity observed at the wall feet. Pre-stressed cables can form a new combined support system with initial lining after the removal of vertical temporary support. This approach effectively avoids stress mutation and mitigates risks during support dismantling. However, its capability to control surrounding rock deformation is slightly weaker than the double-side drift method, resulting in a 39.5% increase in crown settlement (reaching 21.9 mm), the overall displacements remains within safe limits. From the perspective of support optimization, the maximum stress increment in the initial support under unbalanced support measures is only 4.24%. However, these measures significantly reduce the stress deviation between the left and right support structures from 17.8% to 2%, effectively mitigating the asymmetric loading caused by bedding-plane biased pressure. Furthermore, the maximum vertical displacement of the surrounding rock increases by merely 0.57 mm compared to balanced support measures. By integrating indicators of surrounding rock deformation and structural internal forces, it is concluded that the optimization of construction methods under unbalanced support measures can significantly enhance construction convenience and economic efficiency while ensuring structural safety. This approach optimizes the mechanical performance of the support system. The research findings provide an important reference for the design and construction of similar super-large section tunnels under bedding-plane biased Pressure.