Developing high-infrared absorption systems is crucial for improving radiation heat transfer efficiency in high-temperatureTemperature industrial furnaces and achieving energy conservation and emission reduction. Transition metal dopingTransition metal doping is a key method to enhance infrared absorption. Using first-principlesFirst-principle calculations, we studied the effects of B-site doping with Cr, Co, and Ni on the electronic structure and optical propertiesOptical properties of rhombohedral perovskite PrAlO3. The thermodynamicThermodynamics stability of these doped systems was confirmed. By introducing intermediate energy levels, Cr, Co, and Ni doping achieves the regulation of the bandgapsBandgap. At a fixed doping concentration, the bandgapsBandgap of the three systems decrease to 1.851, 2.413 eV, and 0, respectively. The densityDensity of states’ calculations indicates that the intermediate energy level is contributed by the hybridization of transition metal ion 3d orbitals and O ion 2p orbitals. The overall light absorption coefficient curves of the three doping systems shift towards longer wavelengths. Thanks to the disappearance of the bandgapBandgap, Ni-doped PrAlO3Doped PrAlO3 can absorb light in the entire visible and near-infrared bands, making it a potential high-infrared absorption system.