In order to explore drying characteristics and the change law of moisture of straw-based nutrient seedling-growing bowl tray during the drying process, under the conditions of different drying temperatures (50℃, 55℃, 60℃, 65℃ and 70℃), hot air speed (1.0m/s, 1.5m/s, 2.0m/s, 2.5m/s and 3.0m/s) and microwave power (180W, 360W, 540W,720W and 900W), the microwave coupled with hot air drying experiment was carried out for strawbased nutrient seedling-growing bowl tray to study the effects of different drying factors on drying rate and effective moisture diffusion coefficient, and establish a dry kinetic model. The results showed that there were only two stages: falling speed drying and rising speed drying, and there was no obvious constant-speed drying stage during the microwave combined hot air drying process of straw-based nutrient seedling-growing bowl tray. The microwave coupled with hot air drying can significantly increase the moisture diffusion capacity inside the materials and improve the effective moisture diffusion coefficient, and the change law of Deff with variation range of value from 2.29641×10-8m2/s to 6.14736×10-8m2/s was consistent with the law of MR. By fitting 12 dry kinetic mathematical models, the Midilli et al model had the largest R2 average value, the smallest χ2 and eRMSE average values, and there was a good consistency between the value of MR obtained from experiment and the prediction value based on Midilli et al model under different conditions, which indicated that the model was suitable for predicting the change law of moisture content during the drying process of the microwave coupled with hot air. The research results can provide theoretical basis and technical support for the application of microwave coupled hot air drying technology in drying straw-based nutrient seedling-growing bowl tray and other materials. 