This article analyzes the problems of an existing motor-driven bi-disc balancer, namely the error movement, vibration and the long time needed to achieve balancing, and proposes solutions which are employed in the design of a new magnetic-driven bi-disc balancer. The optimal movement principles and methods of their determination have been obtained. The summed bi-disc error-free movement control algorithm was able to simulate any placeholder mode of the discs. The results show that the new movement control algorithm can effectively improve the quality of auto-balancing, achieve error-free movement, zero vibration and a short balancing time.