Abstract: In order to effectively detect the biological toxins in maize, 80% acetonitrile -0.1% formic acid aqueous solution extraction, QuEChERS purification, methanol −0.1% formic acid +5 mmol/L ammonium formate aqueous solution using C₁₈ column and gradient elution separation, electrospray positive and negative ions simultaneous scanning, and multiple reaction monitoring mode synthesis method of gathering data were applied to simultaneously determine nine mycotoxins including aflatoxin B₁, aflatoxin B₂, fumonisin B₁, fumonisin B₂, fumonisin B₃, vomitoxin, 3-acetyl-deoxynivalenol, 15-acetyl-deoxynivalenol and zearalenone. Results showed that, the linear relationship of 9 kinds of mycotoxins were good in the concentration range of 0.25～250 μg/L, the correlation coefficient was above 0.9999, the detection limit was 0.079～1.8 μg/kg, the quantitative limit was 0.26～6.0 μg/kg, the recovery rate was 80.2%～113.8%, the relative standard deviation ≤ 7.7%. Nine mycotoxins were detected in 240 maize samples in Jilin province by this method, in which the aflatoxin B₁, B₂ were not detected, but the other seven toxins were detected. The detection rate of zearalenone was the lowest (14.6%) and FB₂ was the highest (98.3%). This method is simple, sensitive, reproducible and accurate. It is suitable for the simultaneous determination of mycotoxins in maize.