The utility model provides an utilize geothermal water to preheat power generation system that provides multiple forms of energy to complement each other of comdenstion water, includes solar energy light -condensation heat collector, connects gradually over heater, steam generator and pre -heater in the export of solar energy light -condensation heat collector heat transfer medium, the heat transfer medium export and the solar energy light -condensation heat collector heat transfer medium entry intercommunication of pre -heater, the feedwater export of condenser connects gradually condensate pump, geothermal water heater, oxygen -eliminating device, water -feeding pump, high pressure feed water heater, pre -heater, steam generator, over heater and steam turbine, and the generator is connected to the steam turbine, the exhaust gas inlet section of condenser is connected to the steam drain of steam turbine, and the 2nd steam extraction port of steam turbine connects the entry that drawsgas of oxygen -eliminating device, and the 3rd steam extraction port of steam turbine connects the entry that draws gas of geothermal water heater, and a steam extraction port of steam turbine connects the entry that draws gas of stating high pressure feed water heater, the hydrophobic entry of high pressure feed water heater's hydrophobic exit linkage oxygen -eliminating device, the utility modeldiscloses a renewable energy's mesh is utilized to joint high efficiency.