Abstract: The magnetie field adjustable rod (Trim-rod) and its driving system are the important auxiliary device for beam debugging in CYCIAE-230. To get the magnetic field playing a key role in maintaining the beam alignment and extraction, 16 sets of Trim-rods and driving systems were developed. First, the precise linear actuator from Thomson of The United States was used as the mechanical actuator, whose repeated positioning accuracy is ±0.01 mm. Second, the position sensor adopted the linear displacement electronic ruler from Novotechnik of Germany. The repeated positioning accuracy of the electronic ruler is 0.002 mm. In addition, a negative feedback control loop based on PLC module and linear displacement sensor was adopted in Trim-rods movement regulation. In fact, the positioning accuracy and repeatable precision of Trim-rod drive system were 0.05 mm and ±0.02 mm, respectively. Moreover, the system weat through the electrostatic discharge test, electrical fast transient/Brust test and surge immunity test, all met the requirement of YY 0505-2012/IEC 6060 1-1-2:2004. It is proved that the developed Trim-rod driving system can get high positioning accuracy and repeatable precision in high-dose ionizing radiation, high-density magnetic field and narrow space. It is very significant for radial oscillation amplitude minimization, avoiding coherent oscillation and increasing high beam extraction efficiency.