The \({\text{HO}}_{2}\) radical, possessing the lowest excitation energy, plays a pivotal role as an intermediate in hydrogen-oxygen combustion. This study systematically investigates twelve reactions (X +  \({\text{HO}}_{2}\) =XH +  \({\text{O}}_{2}\) , where X = O,H,OH, \({\text{HO}}_{2}\) ) involving both ground-state and excited-state \({\text{HO}}_{2}\) radicals using ab initio methods. Potential energy surfaces (PESs) delineate the reactant and product channels involving singlet oxygen and excited-state \({\text{HO}}_{2}\) , highlighting the feasibility of the excited-state channel S1 with excited \({\text{HO}}_{2}\) . Rate constants calculated from PESs show that those for the excited-state S1 are close to the ground-state T0 at high temperatures, highlighting the significance of excited-state reactions. Then, these findings were used to update kinetic parameters in common hydrogen-oxygen combustion mechanisms like UCSD, GRI-Mech 3.0, and Creck for simulating ignition delay times. The ignition delay times for the updated mechanisms is consistently shorter than those of the original mechanisms, emphasizing the crucial role of excited-state species, particularly \({\text{O}}_{2}\left({\text{a}}^{1}{\Delta }_{\text{g}}\right)\) , and their associated reaction channels in hydrogen-oxygen combustion, especially at high temperatures.