N-dimethylnitrosamine is one of the most toxic nitrosamine compounds and can be produced in the process of food processing or storage. The detection methods are various with tedious operation and low accuracy. QuEChERS pretreatment combined with GC/LC-MS has been widely used in the determination of N-dimethylnitrosamine in food due to its advantages of simple operation， good extraction and purification， high sensitivity， stable recovery and effective improvement of detection rate and throughput. The pretreatment methods， detection equipment and detection parameters of N-dimethylnitrosamine in food were compared to analyze the advantages and disadvantages of different methods.