Developing a simple and efficient method for synthesizing single-atom catalysts is of great significance in promoting the advancement of this field. Here, a one-pot synthesis strategy was successfully employed to fabricate an iridium single-atom catalyst supported on ordered mesoporous carbon-based material. During the preparation process, carbon and nitrogen elements spontaneously anchored iridium species from the initial mixing of reactants, ultimately forming atomically dispersed active sites. The as-prepared catalyst exhibits ordered mesoporous architecture, which not only facilitates rapid reactant contact and mass transfer of reactants, but also stabilizes active centers through spatial confinement effects. The catalyst demonstrates superior catalytic performance and stability in lower alkane dehydrogenation reactions, achieving an iso-butane conversion of 35.3% with 98.7% selectivity for iso-butene at 450 °C (substantially lower than the operating temperature required by conventional Pt-based catalysts). This method provides a novel approach for large-scale preparation of single-atom catalysts and has important application prospects, which are expected to play a significant role in the field of energy catalysis.