In this experiment the pretreatment methods of automatic immunomagnetic bead purification and immunoaffinity chromatography purification were used to quantitatively detect aflatoxin B1 in different edible oils by ultra-high performance liquid chromatography, and the accuracy, spike recovery and detection time of the two pretreatment methods were compared. The results showed that the results of automatic immunomagnetic bead purification and immunoaffinity chromatography purification for the determination of vegetable oil standard materials were 15.59 μg/kg and 14.64 μg/kg, respectively, both of which were within the standard range. Different amounts of aflatoxin B1 standard materials were added to different kinds of edible oils, and the recovery rate of spikes was between 88%~110%, and the relative standard deviation was within 5%. The Bland-Altman method was used to analyze differences between the automatic immunomagnetic bead purification method and the immunoaffinity chromatography purification method, and the results showed that differences between the two purification methods were within the acceptable range. Both methods could meet the experimental requirements in purification and enrichment of aflatoxin B1 in edible oil and can be used instead of each other. Through the comparison of detection time, automatic immunomagnetic bead purification combined with mycotoxin automatic purification instrument pretreatment method can process multiple samples at the same time, and the average purification time of one sample is less than 3 min, indicating that the treatment time is shorter, and the experimental efficiency is higher.