To improve uneven airflow circulation in roof ventilated wood drying kilns,the authors designed two devices.One had horizontal-vertical airflow guidance devices which were installed on the top corner of the kilns,and the other had an adjustable vertical airflow guidance device which was set on the side airway in the kilns.The results showed that average airflow speed and uniform velocity in the air distribution field in the kilns were improved significantly with a shorter drying cycle and better production efficiency.