In order to reduce the harmful effects of nisulfuron on sweet corn, the physiological regulation mechanism of sweet corn detoxi cation was studied. In this study, a pair of sister lines of sweet corn(nicosulfurontolerant"HK310" and nicosulfuron-sensitive "HK320")were used to analyze the effects of nicosulfuron stress on glyoxalase system, hormone content and key gene expression on sweet corn seedlings. The results showed that after spraying nicosulfuron, methyl glyoxal (MG) content in HK301 increased rst and then decreased. As well as, the activities of glyoxalaseI (GlyI) and glyoxalaseII (GlyII), the content of non-enzymatic glutathione (GSH) and the glutathione redox state glutathione/ (glutathione + glutathione disul de) (GSH/ (GSH + GSSG)) showed the same trend as the MG content. Besides, the contents of ababic acid (ABA), gibberelin (GA) and zeatin nucleoside (ZR) also increased rst and then decreased, and auxin (IAA) content increased continuously. In HK301, all indexes after spraying nicosulfuron were signi cantly greater than those of control. In HK320, MG accumulation continued to increase after nicosulfuron spraying, and the activities of GlyI and GlyII and GSH content rst increased and then decreased after 1d stress. The indicators above are signi cantly greater than the control. While the ratio of GSH/ (GSH + GSSG) showed a decreasing trend and signi cantly smaller than the control. Furthermore, the contents of ABA and IAA continued to increase, and the contents of GA and ZR rst increased and then decreased. Compared with HK320, HK301 signi cantly upregulated the transcription levels of GlyI and GlyII genes in roots, stems and leaves. Comprehensive analysis showed that sweet maize seedlings with different drug resistance improved their herbicide resistance by changing glyoxalase system and regulating endogenous hormones. The results provided a theoretical basis for further understanding the response mechanism of glyoxalase system and the regulation characteristics of endogenous hormones in maize under the stress of nianysulfuron.