The invention relates to the air conditioning technology, and provides a communication method and apparatus between air conditioning units for guaranteeing the communication reliability and the communication efficiency the air conditioning units on the premise of ensuring that the wiring is not limited by the space. The method comprises the following steps: during the communication between the air conditioning units, if the wireless channel quality reaches a preset standard, using a wireless communication mode to transmit data, and if the wireless channel quality does not reach the preset standard, using a wired communication mode to transmit data; and as the air conditioning units interacting in the wired communication mode does not share a wireless communication channel, the communication capacity is increased, the channel rate of the wireless communication channel is relatively high, meanwhile a bus mode is used as the backup communication mode of the wireless communication mode, when the quality of the wireless communication channel is worse, the effective data transmission between the air conditioning units is guaranteed, so that a high-quality communication effect can also be achieved by adopting few wired connecting lines, the wiring cost is saved, and the wiring difficulty is reduced as well.