In order to improve the drying quality of fruit and vegetables, microwave-hot-airflow rolling drying (MARD) device was developed, using which the thermal image of carrot slices during drying was measured. In addition, the moisture state and distribution in different drying stages were detected with low-field nuclear magnetic resonance analysis and imaging (NMR/MRI). The dielectric constantε′and dielectric loss factor ε″of carrot slices in the corresponding drying stage were also measured. The dehydration process and drying quality of the materials were analyzed by comprehensive indexes, and the results showed that the drying speed of carrot slices was decreased gradually, and the drying temperature was distributed evenly, and floated in the set range. In NMR spectrum, the water signal was decreased gradually and the main peak was shifted to the left, when the water was changed to the direction of compact combination with dry matter. The MR signal showed that the water distribution was uniform during MARD. With the development of MARD, the ε′and ε″of materials were decreased significantly, and the dielectric loss at the edge was lower than that at the core. With the drying processing, the difference was decreased, indicating the effect of non-uniform microwave drying caused by the difference of dielectric properties would be weakened in the MARD process. The research provided a reference for improving the efficiency and quality of microwave drying of fruits and vegetables.