The invention discloses automatic heat exchange equipment of a gas-fired boiler. The automatic heat exchange equipment of the gas-fired boiler comprises a water containing tank, a waste gas serpentine pipe, a sprayer, a water pump, a circulation pipe, a temperature sensor and a control system. The bottom end of the lateral wall of the water containing tank is provided with a circulating outlet which is connected with the water pump. The circulating outlet is provided with a third valve. One end of the circulating pipe is connected with the water pump, and the other end of the circulating pipe is connected with the sprayer. The circulating pipe is provided with a fourth valve. The temperature sensor is installed at the bottom end of the lateral wall of the water containing tank. The waste gas serpentine pipe is installed inside the water containing tank, and the two ends of the waste gas serpentine pipe stretch out of the water containing tank. The sprayer is installed at the top inside the water containing tank and connected with external water supply equipment through a first valve. Through the automatic heat exchange equipment of the gas-fired boiler, heat in waste gas is converted into heat of water, energy is stored, and waste is avoided; and meanwhile, whether cooling water is supplied or not is judged according to the water temperature, and a certain quantity of energy sources are saved.