Earth abundant transition metal-based materials are widely served as peroxymonosulfate (PMS) activators for degradation of emerging contaminants. However, the agglomeration of catalyst particles and metal ion leaching hinder their practical applications for pollutant decomposition. In this study, a Co₃O₄-carbonized polyaniline composite (Co₃O₄/CPANI) was implemented for PMS activation. The Co₃O₄/CPANI + PMS system exhibited high catalytic performance toward tetracycline (TC) degradation (degradation efficiency of 92.11%, initial TC level of 20 mg/L). Moreover, the practical application potential of Co₃O₄/CPANI + PMS system was well verified with three antibiotics (i.e., TC, doxycycline (DOX), and ciprofloxacin (CIP)) at highest actual aquatic environmental levels (1.0 and 0.5 mg/L). In the established Co₃O₄/CPANI + PMS system, both radicals (•O₂⁻, •OH and SO₄^•-) and non-radical (¹O₂) contributed to TC degradation, and ¹O₂ was the dominant reactive oxygen species (ROS). CO groups, oxygen vacancies (O_VS), redox pairs of Co²⁺/Co³⁺ species, and graphitic N all served as active sites in the PMS activation process, especially, O_VS were crucial for the generation of ¹O₂. This study provides an efficient method for the synthesis of metal-based nanocatalysts with low nanoparticle aggregation and metal leaching which could act as a sustainable PMS activator for the remediation of TC-polluted water environment.