In the surface facilities engineering of shale gas development in Sichuan Basin, dehydration process by triethylene glycol (TEG) is most frequently used to remove the saturated water in raw natural gas to meet the pipeline transportation requirements. The field operation data shows that the energy consumption of the shale gas dehydration unit constructed in the early development stage is relatively high. In order to reduce the energy consumption of the shale gas dehydration unit, taking a 300×10⁴ m³/d(3×10⁶ m³/d) unit as an example, the feed gas inlet temperature, TEG circulation rate, regeneration temperature and lean TEG concentration of the shale gas dehydration unit are optimized. ASPEN HYSYS simulation software with the Cubic-Plus-Association (CPA) Property Package is used in this research, making use of the site operating conditions. The result shows that: 1) under the conditions of feed gas inlet temperature of 35 ℃, TEG circulation rate of 2.5 m³/h, regeneration temperature of 203 ℃, lean TEG concentration of 99.2%, treated product gas meets the requirements of pipeline transportation, and the energy conservation effect of this optimum operating conditions is obvious, as the comprehensive energy consumption for unit output of product is reduced by 42.1%; 2) after optimization, the capital cost of a single set of TEG dehydration unit has been reduced by 16.4%, saving about 2.3 million RMB; 3) compared with the current facilities, each single set of TEG dehydration unit can save 27.4×10⁴ m³/a(274×10³ m³/a) gas and 53×10³ kW·h/a(5.3×10⁴ kW·h/a) electricity, amounting to about 0.301 million RMB of annual operating cost saving. In conclusion, the research result can provide good reference for the design and process optimization of shale gas TEG dehydration unit.