In order to explore the drying characteristics of air-dried chestnut by combined solar energy and heat pump during the drying process, using fresh chestnut and under the conditions of different drying temperatures, airflow rates, loading capacities, the experiment on combined drying of solar energy and heat pump was carried out for air-dried chestnut to study the effects of different drying factors on drying rate and moisture content of dry basis. At the same time, six mathematical models were used to fit the relationship between moisture ratio and drying time in the drying process of air-dried chestnut, and the optimal model was determined. Besides, based on Fick’s second diffusion law, the effective moisture diffusion coefficient of air-dried chestnut under different drying conditions was determined. The results showed that the drying process of air-dried chestnut was controlled by adjusting stage and falling speed drying stage, and the main drying process was falling drying stage. The drying rate of air-dried chestnut was increased with the increase of temperature, the increase of airflow rate and the decrease of the loading capacity. During the drying process, the experimentally observed effective moisture diffusion coefficient values were increased from 3.00124×10-10m2/s to 1.14753×10-9m2/s with the increase of drying temperature and airflow rate, and the decrease of loading capacity. By fitting six mathematical models，the results of comparing the values of the correlation coefficient R2，sum of squares of residuals and the chi-square (χ2 ) showed that the Page model was the optimal model for describing air-dried chestnut by combined solar energy and heat pump, as well as the predicted value fitted well with experimental value obtained. The results would provide a technical basis for the application which was a combination of solar energy and heat pump in air-dried chestnut drying.