S(IV)-based systems used for advanced oxidation processes (AOPs) have been constructed for the degradation of organic contaminants via oxysulfur radicals, including ${\text{SO}}_3^{•-}$, ${\text{SO}}_4^{•-}$, and ${\text{SO}}_5^{•-}$. Although ${\text{SO}}_5^{•-}$ is proposed as an active species in AOPs processes, research on the reactivity of ${\text{SO}}_5^{•-}$ has remained unclear. In this work, 53 target aromatic micropollutants (AMPs), including 13 phenols, 27 amines, and 13 PPCPs were selected to determine the second-order reaction rate constants for ${\text{SO}}_5^{•-}$ using the competitive kinetics method, in which the $k_{{\text{SO}}_5^{•-}}$ values, observed at pH 4 ranged from (2.44 ± 0.00) × 10⁵ M⁻¹ s⁻¹ to (4.41 ± 0.28) × 10⁷ M⁻¹ s⁻¹. Quantitative structure-activity relationship (QSAR) models for the oxidation of AMPs by ${\text{SO}}_5^{•-}$ were developed based on 40 $k_{{\text{SO}}_5^{•-}}$ values of amines and phenols, and their molecular descriptors, using the stepwise multiple linear regression method. This comprehensive model exhibited the excellent goodness-of-fit ($R_{\text{adj}}^2$ = 0.802), robustness ($Q_{LOO}^2$ = 0.749), and predictability ($Q_{ext}^2$ = 0.656), and the one-electron oxidation potential (E_ox), energy of the highest occupied molecular orbital energy (E_HOMO), and most positive net atomic charge on the carbon atoms (qC⁺) were considered the most influential descriptors for the comprehensive model, indicating that ${\text{SO}}_5^{•-}$ oxidizes pollutants via single electron transfer reaction and exhibits a strong oxidation capacity, especially for pollutants containing electron-donating groups. Moreover, the $k_{{\text{SO}}_5^{•-}}$ values of 13 PPCPs were predicted using this comprehensive model, which suggested the practical application significance of the QSAR model. This study emphasizes the direct oxidation capacity of ${\text{SO}}_5^{•-}$, which is important to evaluate and simulate AOPs based on S(IV).