Oscillation of the valve position of the actuator is a common phenomenon in the automatic control. The frequency of the oscillation is also high. Because of the existence of this oscillation phenomenon, it is very easy to cause the fault of the magnetic amplifier. In addition, the oscillation of the electric actuator often affects the service life of the actuator. Therefore, this oscillation should be eliminated in the regulating system to ensure the normal operation of the regulating system There are many reasons for the oscillation of the actuator valve position. In this paper, combined with the experience of design, installation, commissioning and operation, the reasons the actuator oscillation and the methods to eliminate them are described. (1) Oscillation of the valve position feedback small loop of the electric actuator, the main for the oscillation are as follows. a) Because the magnetic amplifier is too sensitive, the dead zone △ g of the magnetic amplifier is too small, so that the loop of the actuator can not be stable and oscillation is produced. b) When the actuator loses the braking effect and produces the phenomenon of inertia, it will also the oscillation of the small loop of the actuator. According to the above causes of the actuator oscillation, the magnetic amplifier is not sensitive to △ g, which too small to cause oscillation. According to the experience in operation, the dead zone △ g of the magnetic amplifier can be adjusted to ± 120-140 A to eliminate the small loop oscillation. For the loss of braking of the actuator, the cause of the loss of braking of the actuator should be found out and eliminated. (2) Oscillation of the actuator caused by the fluctuation of the signal source. Damping can be added to the system design, and damping devices can be added the circuit. The method of mechanical damping is used to reduce the fluctuation of the output signal of the transmitter, so as to eliminate the oscillation of the actuator. () The system oscillation caused by the improper adjustment of the regulating system parameters, which causes the oscillation of the actuator. Improper adjustment of the parameters of the regulator cause the system to produce different degrees of oscillation. For the single loop regulating system, if the proportional band is too small, the integral time is too short, and the differential time differential gain are too large, the system oscillation may be produced. For the multi-loop system and the single-loop system, in addition to the problems in common, there are mutual influences between loops. Because of the improper adjustment of parameters, there is a resonance between loops. For the above reasons, the oscillation of the actuator may be caused These parameters may be reasonably selected during the system adjustment, so that each loop should keep the required stability margin. (4) The regulating valve flow characteristics are too steep or valve operates at a small opening, which causes the regulator to overshoot and cause the actuator to oscillate. When the regulating valve flow characteristics are too steep, a small deviation the setpoint will cause a large change in the adjusted medium, often causing excessive regulation and causing the system to oscillate. Because the characteristics of the regulating valve are limited by process conditions, it is difficult to modify. The proportional band of regulation can be increased appropriately to improve the quality of regulation. (5) Due to the clearance and clearance the connecting piece of the actuator with the link rod and the regulating valve stem. All connecting pieces shall be manufactured according to the three-level precision fit. The oscillation the actuator is a common fault phenomenon in operation, which directly affects the quality of regulation. The internal reasons are also various. When analyzing and queuing the fault reasons, we analyze the fault reasons from the aspects of system composition, installation and commissioning, and then try to eliminate them