The exciting force of the SJ-YA series Circular Vibrating Screens in the whole process of vibration is handled by an unbalanced eccentric shaft and its additional eccentric block rotation together. Due to its design, it makes up for the shortage of exciting force generated by single shaft vibration and by single block vibration. Its vibration direction is similar to a circular motion curve. The screen surface is tilted 20 degree, and it is good for screening larger stones, and achieves an effective utilization of electric power. It is both practical and economic.