The small gap between rapeseed could cause difficult heat dissipation and seed drying, and result inmildew of rapeseed. To tackle this problem in production, we designed a spin dryer on the principle of dryingrapeseed with cyclone airflow. Base on the force analysis of rapeseed following the airflow movement in thedrying chamber, we discovered the relations between the size of grading hole and the moisture content ofrapeseed, and designed the structure of air blower and heater, then tested the demo dryer. The results showedthat when inlet tempe...