Turning operation of slender shaft poses a great challenge in machining field. It is due to the fact that the accuracy of machined workpiece depends almost completely on the operator’s skill by using conventional methods. To improve the accuracy of slender shaft with less operation skill, this paper presents an error compensation system, which includes a fuzzy PID controller. As a part of the controller, the traditional PID controller is used to control a follower rest for improving the dimensional accuracy. And the fuzzy controller incorporates skilled operators’ knowledge into an automatic machining system. At the end, turning experiments are carried out to verify the efficacy of the error compensation system. The experimental results indicate that the dimensional accuracy of slender shaft using the system is higher and more stable than that by using conventional methods.