In view of the problem of long time and high energy consumption of macadamia nuts of drying, the infrared drying characteristics were analyzed and a mid-infrared dryer was designed. The mid-infrared drying characteristics reasch of macadamia nuts were carried out. The changes of dry moisture and rate were analyzed. The dry-diffusion and activation energy conditions were established and a mid-infrared drying model was established. The results showed that the moisture content of macadamia nuts decreased to 1.36% after 360 minutes under the drying conditions of 60 ℃ and 0.8 kW in the middle infrared emitter. The whole drying stage was mainly slow drying. The Midilli-Kucuk model could effectively predict the moisture change mechanism of macadamia nuts in the middle infrared drying process and the Australian firmness in each period. The effective water diffusion coefficient was between 2.03×10^-7 and 2.31×10^-7 m2/s. The drying activation energy of macadamia nuts was calculated by Arrhenius formula.