An air temperature adjusting system includes a gas-liquid mixing device, a temperature adjusting device, a gas-liquid separating device and a gas-liquid circulating device for driving gas-liquid to move among the gas-liquid mixing device, the temperature adjusting device and the gas-liquid separating device. The gas-liquid mixing device is for absorbing air into liquid to mix the air with the liquid and bringing a mixture of the air and the liquid into the gas-liquid separating device after a temperature of the mixture is adjusted by the temperature adjusting device; and the gas-liquid separating device is for separating the air with the liquid. The gas-liquid mixing device includes at least one T-shaped pipe, wherein a main pipe of each T-shaped pipe is interconnected; a branch pipe of each T-shaped pipe has an opening intercommunicated to the air.