Abstract: In the weaving process, yarn’s tension is changing, how to track and control it has become one of the most difficult problems. In order to reduce the tracking error, and simplify the tracking control problem of yarn tension, this paper puts forward a kind of control method of yarn tension based on right coprime factorization. The design of yarn tension model, based on the theory of right coprime factorization and three element model, will be obtained by mathematical calculation. The tracking control design will be designed and proposed with the yarn tension model and will be proved by the simulation in Matlab/simulink. Through the verification of theory and simulation system design of yarn tension, the tracking control method based on the right coprime factorization is able to track and control yarn tension.