Abstract: A method for separation and determination of squalene in plant oil by gas chromatography-mass spectrometry(GC-MS/MS)was established. After ultrasonic saponification with potassium hydroxide-ethanol solution,the n-hexane solution was extracted and concentrated with nitrogen blowing,and the n-hexane was dissolved. The extract was separated by an HP-5MS column and then detected by a mass spectrometer,and quantified by an external standard method. The method had a good linear relationship(r=0.9998)in the range of squalene concentration 0.1~100.0 mg/L,the RSD of the method was 1.00%~3.35%,and the recovery rate of spiked was 83.60%~110.44%,the average recovery rate of spiked was 98.89%,and the detection limit(RSN=3)of the method was 0.10 mg/L. The analysis of four types of actual oil samples by gas chromatography-mass spectrometry and gas chromatography showed that the gas chromatography-mass spectrometry method has the advantages of high efficiency and rapidity,simple operation,low pollution,and high detection sensitivity,which can meet the rapidity of squalene in vegetable oil,high-throughput detection.