Tetrahydrothiophene is commonly used as an odor additive in combustible gas to track of gas leaks. In order to develop a method by using portable headspace gas chromatography with mass spectrometry (HS-GC/MS) to determine tetrahydrothiophene in soil, orthogonal test was adopted to optimize the parameters of headspace injection, including different equilibrium temperature and time, different injection pressure and different GC/MS detection parameters. Results showed that:1) The optimal conditions for headspace injection were equilibrium temperature 80℃, equilibrium time 20 min, and injection pressure 100 kPa. 2) The heating procedure of the portable GC/MS as follows:the initial column temperature was 60℃, kept for 2 min, then raised up to 90℃ at 10℃/min, kept for 4 min, and to 200℃ at a rate of 20℃/min, kept for 10 min. 3) Under such conditions, the detection range for this method of tetrahydrothiophene concentration was between 0.005 mg/kg and 10.000 mg/kg, recovery rate between 82.4%-98.5%, intraday and intraday precision relative standard deviation between 4.6%-7.5%. The established method is fast, efficient and repeatable, and can be used to on-site detect tetrahydrothiophene in soil.