In　this　paper,　the　control　system　of　a　600MW　supercritical　lignite-fired　boiler　was　modeled　and　coupled　with　boiler　thermal　system　through　GSE　simulation　software.　Simulation　experiments　were　conducted　under　load　decrease　condition　and　load　rise　condition　in　order　to　test　control　effect　and　analyze　efficiency　change　in　the　dynamic　mode.　Simulation　results　show　that　the　applied　control　strategies　and　established　control　model　are　reliable　and　effective.　From　BMCR　condition　to　THA　condition,　boiler　efficiency　falls　from　92.08%　to　91.71%,　then　slowly　increases　to　92.02%.　From　THA　condition　to　75%THA　condition,　boiler　efficiency　drops　from　92.02%　to　91.42%,　then　slowly　rises　to　91.90%.　From　75%THA　condition　to　45%BMCR　condition,　boiler　efficiency　slumps　from　91.90%　to　91.37%,　then　gradually　ascends　to　91.76%.　From　THA　condition　to　BMCR　condition,　boiler　efficiency　rises　from　92.02%　to　92.30%,　then　slowly　decreases　to　92.08%.　From　75%THA　condition　to　THA　condition,　boiler　efficiency　soars　from　91.87%　to　92.41%,　then　slowly　falls　to　92.02%.　From　45%BMCR　condition　to　75%THA　condition,　boiler　efficiency　ascends　from　91.76%　to　92.24%,　then　gradually　drops　to　91.87%.　Load　rise　condition　undertakes　lower　energy　losses　than　load　decrease　condition.　©　2015　The　Japan　Society　of　Mechanical　Engineers.