Abstract: Gas turbine combined cycle power generation has become one of the main development directions of current thermal power generation. The cost model of gas turbine combined cycle was established based on the thermoeconomic structural theory, the influences of different gas turbine operation strategies on the unit thermoeconomic cost of product of gas turbine combined cycle unit were analyzed. And, the evaluation analysis of the gas turbine combined cycle was performed based on the evaluation index. The effects of natural gas prices and non-energy costs on the thermoeconomic costs of each component were analyzed. The results show that changing the gas turbine operation strategy can reduce the unit thermoeconomic cost of product. By analyzing the performance evaluation index values of each component, the results show that for the air compressor and steam turbine, reducing investment costs is the main improvement direction. For the combustion chamber, the cost of negative entropy due to irreversible losses can be reduced by improving the combustion efficiency of the combustion chamber and reduce the energy conversion loss from the fuel chemical energy to thermal energy of flue gas. Through sensitivity analysis, the results show that the change of natural gas's price has the greatest impact on the unit thermoeconomic cost of the combustion chamber, and non-energy costs have the greatest impact on the unit thermoeconomic cost of the air compressor, gas turbine and steam turbines.