The model of air leakage flow was constructed based on air infiltration mechanism of multi-temperature refrigerated truck. Theoretical analyses and experimental measurement were conducted with the established model, such as internal partition coefficient, load coefficient, internal flow disturbance coefficient, heat pressure difference and other parameters. It was shown that the air leakage rate was mainly affected by air tightness of the vehicle itself, speed, internal partition, loading condition and airflow disturbance. Specifically, the internal partition could improve air tightness of the vehicle with diminishing utility. The internal partition coefficient was 0.6~0.9 in double temperature refrigerated truck, and it was 0.45~0.85 in the three temperature refrigerated truck. The internal loading capacity had limited effect on air infiltration. The load coefficient was 0.98, 0.96, 0.92 and 0.87 when load was 25%, 50%, 75% and 100%, respectively. The influences of internal airflow disturbance were different with different speeds. The internal flow disturbance coefficient was 0.68, 0.85, 0.94, 0.97 and 0.98 when speed was 20km/h, 40km/h, 60km/h, 80km/h and 100km/h, respectively. Since the multi-temperature refrigerated truck used for city distribution is often at low speed, the internal circulation wind could stop air leakage at a certain degree. In addition, the heat pressure difference caused by temperature difference between inside and outside of the truck was small because the height of refrigerated truck was small. Theoretical analyses showed that temperature difference of 25K corresponded to pressure difference of 1Pa. Such effect was so insignificant in engineering practice that the air infiltration of refrigerated truck can be regarded approximately as a result of simple wind pressure.