An accurate simulation for externally prestressing tendon of structure is the key problem of finite element analysis. An long-span concrete continuous rigid frame bridge with arrangement of internal and external tendons is taken as example, simulation of externally prestressing tendon by using truss elements with rigid arms and external tendons elements for free sliding are made respectively. The proposed method of analysis is formulated for considering shrinkage and creep of concrete as well as segmental construction, which external tendons elements for free sliding are based on the external tendons are members for the normally elastic strain caused by the free sliding between external tendons and deviators. Some numerical examples are solved to verify the reliability and correctness of the various models.It is shows that there is little difference between the internal force and deflection of the continuous rigid frame bridge under three different calculation methods, but there is a big difference in the stress of external tendon ,in the case of accurate calculation of the stress of external tendon, the calculation of similar bridges should be carefully considered.