Efficient recovery of low carbon light hydrocarbons from natural gas has important economic value. To accurately determine the ability of natural gas produced in different blocks of the Tarim oilfield to produce liquid hydrocarbons at low temperature（243.15 K）, natural gas samples were obtained from the on-site treatment station by using the pressure preserving sampling method, and then the high-pressure and low-temperature phase equilibrium experiment was carried out. Based on the results of the phase state experiment, the thermodynamic prediction model of natural gas flash was established. Finally, combined with material balance, the liquid hydrocarbon capacity of natural gas at low temperature was determined. The potential liquid hydrocarbon production of seven natural gas samples, TZ（processing station code, the same as below） is 596.42 g/m~3, YH is 177.10g/m~3, DN is 145.52 g/m~3, LN is 39.23 g/m~3, DB is 27.28 g/m~3, KL is 4.59 g/m~3, and YM is 60.23 g/m~3. The results of the study match well with the actual field data, and have a guiding role in setting the operating conditions of on-site natural gas treatment stations and constructing low-temperature dehydrocarbon devices.