In order to improve drying quality, reduce manpower intensity and realize automatic drying, a reversible airflow drying system based on single chip computer control was developed. Utilizing the technological process, "reversible airflow and deep bed drying indirectly", the performance experiments and analyses of the system were carried out. The function and effect of the inverse air current and the inner outer air current cycle in the drying process were discussed. By using the system and the technological process, the qualities of the dried materials, seeds especially, can be ensured effectively.