The utility model discloses an automatic air distributing system which comprises a mixing chamber, at least one gas supply device, at least one work chamber, solenoid valves, a remote computer, flow controllers and flow control cards, wherein the mixing chamber is provided with at least one gas inlet and at least one gas outlet; the at least one gas supply device is connected with the gas inlet of the mixing chamber through an input pipeline; the at least one work chamber is connected with the gas outlet of the mixing chamber through an output pipeline; the solenoid valves are arranged on the input pipeline and the output pipeline; the remote computer is electrically communicated with the solenoid valves; the flow controllers are arranged on the input pipeline; and the flow control cards are electrically communicated with the flow controllers in a one-to-one correspondence way. According to the automatic air distributing system disclosed by the utility model, accurate mixing matching of various gases can be realized according to the preset proportion through remote control; and meanwhile, the air distributing efficiency is increased and labor force and labor hour are saved.