Abstract: Taking PG9171E gas-steam combined cycle power plant as the research object, in this paper the combined cycle and intake cooling systems were modelled. The performance changes of the gas turbine side, the heat recovery steam generator side and the steam turbine side of the unit with the inlet cooling system were then analyzed. The results showed that for every 10 degrees of the temperature rise, the output of the E-type combined cycle unit with the intake cooling system will increase by about 9 % while the efficiency of the heat recovery steam generator is reduced by 3%. In addition, by properly tuning steam parameters and taking full advantage of the waste heat resources the steam turbine will generate more output by about 2.1MW and the combined cycle efficiency can be improved by about 0.3%.