Abstract: In this study, the effects of point defects and N doping on the electronic, magnetic, and optical properties of the two-dimensional β-Ga₂O₃ system were investigated using first-principles calculations based on density functional theory. The results show that after N doping, the two-dimensional β-Ga₂O₃ system introduces impurity energy levels, leading to spin polarization, a reduction in the band gap, and enhanced electrical conductivity. When oxygen vacancies coexist with N doping, the Fermi level moves into the bottom of the conduction band, forming an n-type semiconductor and further enhancing the system's conductivity. The peaks of both light absorption and energy loss in the doped system shift to lower energy levels and decrease in intensity. This broadens the light absorption range, enhances light energy storage, improves transmittance, and contributes to the material’s electrical conductivity. The N-doped two-dimensional β-Ga₂O₃ system exhibits magnetism. This study provides a theoretical basis for optimizing the properties of two-dimensional β-Ga₂O₃ materials and for designing novel optoelectronic and magneto-optical devices.