Abstract: As an abundant agricultural residue, the efficient utilization of corn stover is of great significance for reducing agricultural residue pollution and promoting resource recycling. In this study, corn stover was treated with a cooking system comprising formic acid combined with either guaiacol or syringol to suppress lignin condensation, promote the dissolution of lignin and hemicellulose, and improve the performance of the resulting pulp material. The results showed that this system significantly increased the pulp brightness from 43.4% (obtained with formic acid alone) to 58.9% and 56.1%, respectively. The cellulose content exceeded 80%, while the lignin content was below 2.1%. The tensile index of the paper reached 23.5 N·m/g and 22.9 N·m/g, respectively. The addition of guaiacol reduced the surface lignin coverage of the resulting pulp from 60% to 56%. Hemicellulose components were effectively degraded and separated. These findings demonstrate that regulating lignin-like small molecules can facilitate efficient lignin separation and the production of high-brightness pulp. This work provides a new approach for preparing high-quality corn stover pulp materials and achieving green, high-value utilization.