In this study, a novel covalent organic framework material, g-TPYP-COF, was systematically investigated. By leveraging the time-dependent density functional theory (TDDFT), the first 100 excited states of its monolayer structure were precisely calculated to comprehensively explore the material's optical absorption properties within a specific energy interval. Initially, first-principles calculations were performed to obtain the stable two-dimensional porous planar structure of g-TPYP-COF along with its key structural parameters. Subsequently, an in-depth electron-hole analysis was carried out, and it was conclusively determined that the eight main excited states were all of the local-excitation type. Finally, the ultraviolet-visible (UV-vis) spectrum was simulated. The results clearly revealed a remarkable correlation between the oscillator strength and the UV-vis absorption spectrum. It was found that the material exhibited a strong optical response mainly in the blue-violet light band, with an extremely high maximum absorption intensity of 8,564,470 L mol-1 cm-1. Collectively, these results firmly demonstrate that g-TPYP-COF holds great potential as a high-performance light - absorbing material, which could open up new opportunities for its applications in various optoelectronic fields.