A control method for an automobile air conditioner circulating air door comprises the following steps of (a) initialization, (b) signal obtaining, (c) calculation of the program number according to obtained signals, wherein the program number is the comprehensive expression quantity of the current environment, (d) setting of internal circulation or external circulation according to the magnitude relationship between the program number and relevant set parameters, (e) judgment of the magnitude relationship between automobile speeds and an automobile speed critical value to determine whether internal circulation needs to be set forcedly, and (f) redoing of the step (b), and starting of the next program loop. The control method has the advantages that internal circulation and external circulation can be judged more accurately according to the program number which is obtained through calculation of various parameters, such as environment temperature, sun radiation intensity, automobile speeds, temperature in an automobile and the control objective of the temperature in the automobile. In addition, whether internal circulation needs to be set forcedly is determined by judging whether the automobile speed is too low, pre-judging of the outside air quality can be achieved, and high intelligence is achieved.