The invention relates to a compressed air energy storage power generation system. The system comprises an air heater for heating air to generate high-temperature and high-pressure gas, fuel supply equipment for supplying a fuel to the air heater, power generation equipment for generating electricity by using the high-temperature and high-pressure gas generated by the air heater, and gas supply equipment comprising a compressor connected with a power generation power grid for generating high-pressure gas and a gas storage tank for storing the high-pressure gas, wherein the gas storage tank is communicated with an air inlet of a combustion chamber of the air heater by a first pipeline for supplying combustion assisting gas; the gas storage tank is communicated with a guide nozzle in the combustion chamber by a second pipeline; the axis of the guide nozzle extends from the side wall of the combustion chamber to the axis direction of the combustion chamber; the direction of combustion flame in the combustion chamber is controlled; the gas storage tank is communicated with a mixing chamber of the air heater by a third pipeline; and the mixing chamber is communicated with a gas outlet end of the combustion chamber to mix combusted gas with un-combusted high-pressure air for adjusting the pressure and the temperature of gas flowing out the air heater from the mixing chamber.