Abstract: This study systematically analyzes the energy consumption characteristics of a 9HA.01 gas-steam combined cycle unit under condensing and cogeneration modes, based on performance test data. The test results show that: At 100% load, the combined cycle efficiency reaches 63.98% (condensing mode), with an equivalent net coal consumption rate of 194.79 g/(kWh). At 50% load, efficiency drops to 58.86%, while coal consumption rises to 213.66 g/(kWh). For every 10% reduction in load factor, the net coal consumption increases by an average of 2.1 g/(kWh). The cogeneration mode demonstrates significant energy efficiency advantages, achieving 67.28% efficiency with 150 t/h heat supply, reducing net coal consumption to 185.56 g/(kWh). The primary energy consumption bottlenecks include excessive condenser terminal difference (up to 5.93 ℃) and declined compressor isentropic efficiency at low loads (83.84% at 50% load) and elevated auxiliary power ratio (reaching 2.32% at 50% load).Proposed energy-saving solutions-including optimization of sliding pressure operation curves, frequency conversion retrofitting for circulating water systems, and deep utilization of waste heat-are projected to significantly reduce the net coal consumption rate and save standard coal.