With the rapid development and technical support by microelectromechanical systems, a lab-on-a-chip or micrototal analysis system has been widely developed for medical tests due to its low cost, simple, disposable, and less contamination. Comparing to the continuous microfluidics system, a digital microfluidics system has the advantages of being without micropump and easily driven using the alternative change of hydrophilic and hydrophobic properties. A feedback control system is proposed for driving digital microfluidics by using capacitive catenary as a sensor. In the proposed system, the moving droplet can be real-time positioned and controlled to overcome the imperfection of fabricated devices and the environmental disturbance. Furthermore, with the compensation of adjusting the amount of applied voltage online, the droplets can run smoothly toward the desired position in the chip through the feedback control. As a result, the proposed system is capable of moving droplets with higher speed, compared to most of the existing system, and improves the reliability of handling microfluidics. The chip for microfluidics operation has been successfully fabricated. With the self-designed circuit and LabVIEW interface, the experiments for operating microdroplets in an open channel are conducted to verify the performances of proposed devices.