Abstract: Aspen HYSYS software was used to simulate the process of natural gas dehydration in an offshore gas field Central Processing Platform. The main operation conditions were as follows: the capacity of natural gas is 175×10⁴ m³/d(15.6 ℃, 101.325 kPa) with the contactor operating pressure and temperature is 9000 kPa and 35 ℃ respectively. The optimal process conditions could be obtained by simulating and optimizing the lean TEG circulation rate, lean TEG mass fraction, reboiler temperature and stripping gas rate. It was verified on site that the natural gas dehydration and regeneration system operated normally under above operation conditions. The water content of the export dry gas met the specification requirement which was less than 30 mg/m³.