When tunnels with extra-large cross-sections pass through layered rock formations, given the unique structural characteristics of these layers, suitable control strategies must be implemented to mitigate any adverse impacts. Based on the extra-large section tunnel project of Chongqing Guobo Center Station passing through layered rock, numerical simulations, and field monitoring are adopted in this study to compare the mechanical differences between balanced and unbalanced anchor cable supports during tunneling. The results show that compared with the balanced anchor cable support, the influence of the unbalanced anchor cable support on the control difference of displacement and plastic zone of surrounding rock is not significant. However, the unbalanced anchor cable supportcould significantly affect the bending moment distribution range of the vault of lining structure, while having little influence on the peak bending moment and the distribution and magnitude of axial force, with the differences between them being 8% and 11.2% respectively. The reduction in the safety redundancy of the lining structure under the unbalanced anchor cable support is less, and the stability of the tunnel in layered rock could still be maintained. From the perspectives of economy and construction convenience, the amount of anchor cable could be saved by 51%, and the economic advantages are more prominent, which is more advantageous in the construction of tunnels with large sections in layered rock. The effectiveness of the unbalanced support in maintaining tunnel stability is confirmed by field monitoring. The discrepancy between the numerical simulation and field monitoring results is merely 2 mm, demonstrating high consistency and validating the accuracy of the calculations. Critical insights for the design and construction of future similar tunnels in layered rock are provided.