In this study, by using the first-principles calculations based on density functional theory (DFT), the electronic aspects of GeP2S monolayer under the effect of buckling variation parameter (μ = 0, 2, 4, 6) are theoretically investigated by the PBE-GGA approximation method, and the obtained results have been compared with previous similar structures. We presented the imaginary part of the dielectric function and absorption spectra for in-plane and out-of-plane polarization of GeP2S monolayer by PBE, HSE06, and TD-HSE06 methods. Also, optical aspects for this 2D nanostructure are presented in out-of-plane polarization under buckling variation conditions up to μ = 6. It was shown that particularly for the range of visible light spectrum its optical behaviors match with its electronic ones. Consequently, the obtained results suggest GeP2S as a suitable material for designing optoelectronic devices.