Hydrogen, with its advantages of high calorific value, abundant source and zero pollution, can significantly reduce CO2 emissions by replacing natural gas in gas turbine power generation, which is conducive to the early achievement of the dual carbon goal. In this study, we adopt a modular modeling approach to develop a predictive model for the characteristics of a gas turbine and its combined cycle system under full operating conditions, and analyze the operating parameters, component operating characteristics and unit energy consumption of the gas turbine unit at full load and partial load when the hydrogen doping ratio ranges from 0 to 100%. The results shown that: compressor power consumption, turbine power, gas turbine power, specific work and power generation efficiency, and combined cycle efficiency all increase with the increase of hydrogen blending ratio, and this trend is more obvious when the hydrogen blending ratio is higher; the effect of hydrogen volume fraction on unit performance at partial load is basically the same as that at full load, but the magnitude of the effect is different; in general, increasing the proportion of hydrogen in fuel can improve the overall unit performance. Overall, the overall performance of the unit can be improved by increasing the proportion of hydrogen in the fuel, but the enhancement effect is slightly weakened as the load decreases.