Abstract: A mechanical system with fast automatic precision location function is studied and analyzed.A mathematical model of the system is given in this paper.Using the model,the dynamic analysis about the system is made and the dynamics of the system is gained.According to the results,the control closed system is finished.The experiment of the system is proved to be good and it is shown that the system can satisfy the requirement,which is a good example for combining machinery with electronics.The method of the device has significance for the system of precision location.