The study employed UHPLC-Q-TOF-MS to analyze zearalenone (ZEN) in maize processed by high-temperature and high-pressure extrusion. The degradation efficiency and degradation products were investigated. The results demonstrated that ZEN degradation rates ranged from 62.5%~78.4% under a conditions of 20% moisture content and 1.3 MPa pressure. Through UHPLC-Q-TOF-MS qualitative analysis using, nine ZEN degradation products of ZEN were identified, including zearalenone, α/β-zearalenol, cleavage fragments of zearalenone, and six hydroxylated zearalenones. The molecular formulas, exact molecular weights, and molecular structures of all nine degradation products were determined. Based on the positions of chemical bond cleavage, the rupture of certain toxic sites, providing both critical experimental data and theoretical support for further research on the ZEN degradation mechanism.