Kiwifruits were respectively dried by freeze-drying and vacuum-microwave combined drying, with different microwave power (0.25, 0.30 and 0.39 W/g). In combination with the shrinkage ratio, sensory quality, color difference, rehydration ratio and porosity of kiwifruit in the drying process, the drying characteristics, pore structure and shrinkage characteristics of kiwifruit pieces in the drying process were analyzed, and the shrinkage model of kiwifruit pieces in the process of FD pretreatment vacuum microwave drying was established. The results showed that the drying characteristics of kiwifruit slices changed with the different power of microwave, and the higher the microwave power could cause higher sensory score of kiwifruit slices, less color difference, larger the rehydration ratio, and larger the shrinkage ratio. It was found that the larger volume could made the greater porosity of kiwifruit slices. However, during the drying process progresses, the lower moisture content of kiwi slices resulted in smaller shrinkage ratio. The optimal shrinkage model of kiwi slices was SR=k₁+k₂MR+k₃(MR)², R²＞0.99, RSS＜0.001, which could well reflect the changes of volume shrinkage of kiwi slices in the process of freeze-drying and vacuum-microwave combined drying.