A power generation system, including: a solar energy concentration system, a biomass gasification device, a gas-powered generator, a steam turbine, a steam-powered generator. The solar energy concentration system is connected to a solar energy heat exchange system. The biomass gasification device is connected to the gas-powered generator. The gas outlet of the gas turbine is connected to the gas exhaust heat system. The second steam outlet of the gas exhaust heat system is connected to the second and the third cylinders of the steam turbine. The first steam outlet of the gas exhaust heat system and the steam outlet of the solar energy heat exchange system are connected to a steam mixing regulating system. The mixed steam outlet of the steam mixing regulating system is connected to the first cylinder of the steam turbine.