Automatic addressing method for air conditioning system and air conditioning controller

The invention discloses an automatic addressing method for an air conditioning system. A first air conditioning serves as a master machine and the other air conditionings serve as slave machines. The method comprises the following steps that: the master machine sends broadcast information to notify the slave machines to enter an automatic addressing mode and the slave machines restore the addresses per se to initial addresses; the master machine transmits the addresses to be allocated, wherein the addresses to be allocated add one automatically, the slave machines receive the addresses to be allocated and transmit response information which comprises the allocated addresses to be competed by the slave machines and the MAC addresses of the slave machines; if receiving the response information from the slave machines, the master machine transmits the address acknowledgement information which comprises the allocated addresses successfully competed by the slave machines and the MAC addresses of the slave machines