A joint heating system of gas combined cycle and solar power and a dispatching method thereof, the user adopts two ways of the hot water radiator and the heat pump to supply heat, wherein the hot water comes from the gas combined cycle units, the electric power comes from the combination of the gas combined cycle units and the solar power generation units, and after detecting the power supplying and power consumption of the user in a historical time period by the comprehensive dispatching and controlling device, a future time period is predicted, and then dispatching is processed on the basis.