Abstract: In order to study the optimal process of hot air-assisted microwave drying of straw-based nutrient seedling-growing bowl tray under different conditions, the drying rate and deformation variables of straw-based nutrient seedling-growing bowl tray were used as indicators, and the effects of microwave power, heating temperature and hot air velocity on the hot air-assisted microwave drying process of straw-based nutrient seedling-growing bowl tray were studied by using the response surface, and a quadratic polynomial regression model was established, and the drying process was optimized. The results showed that the regression model has high fitting ability, which can better describe the drying process of straw-based nutrient seedling-growing bowl tray. The optimal process parameters of hot air-assisted microwave drying of straw-based nutrient seedling-growing bowl tray were microwave power 1600W, heating temperature 60°C, hot air speed 15m/s, the fastest drying rate was 4.015%/min, and the minimum shape variable was 1.522cm. This study provides important theoretical support and technical support for promoting the promotion and application of straw-based nutrient seedling-growing bowl tray.