This paper establishes the dynamic model of the long distance steel belt friction transmission with multi-body system rigid-flexible coupling dynamics theory, employs the boundary element theory to research the setting of the boundary conditions, and then improve the reliability of the simulation and calculation. This paper simulates and analyzes the relationship between pre-load and load,as well as that between stress and strain,so that gets the better transmission accuracy. Starting with experiment, this paper researches on the tension characteristics, running deviation and transmission accuracy of the long distance steel belt. by comparing the result of the simulation, this paper obtains the fitting function of the pre-load of the long distance steel belt and proves it have high transmission accuracy under certain condition which has proper pre-load and load.The experiment shows that the home-made precision friction transmission testbed has the ability of precision transmission. Taking advantage of the friction transmission features of steel belt, it can solve the low transmission accuracy of conventional belt transmission which results from small Elastic modulus and big elasticity sliding motion, and fulfills the long distance friction transmission on the engineering, the deviation can be smaller than 0.5%.