Abstract: To solve the change of Web diameter resulting in the warp tension and velocity becoming more complicated, time-varying and non-linear, which has a severe influence on performance of let-off system controller, such as stability, accuracy and dynamic performance, this paper presents a warp tension and velocity decentralized control with servo controller as actuator. First, an accurate dynamic model is developed for the let-off system; Second, the let-off system is decoupled into the constant tension control and the velocity control; Finally, a strategy for computing reference velocity of let-off is presented, which integrated with feed-forward control, PID control, being composed of the constant tension controller. An experimental analysis between general decentralized PI controller and proposed decentralized controller show that proposed decentralized controller is capability of suppressing the disturbance more effectively and has better accuracy, faster response, more robust and wide range of applications broader.