Abstract: A three-dimensional FE (finite element) model was established for a long-span arch and rigid frame combination bridge using software SAP2000 in order to solve the problem of interaction induced by tensioning the tie bars of rigid frame and main span and adjust its internal forces and geometry. To meet the requirements for stresses and deformations in the key locations of the combination bridge, reasonable tensioning forces were determined on the basis of construction processes. The result shows that the tensioning force of main span is mainly undertaken by rigid frame. Finally, it was pointed out that the influence of geometrical nonlinearity on internal forces may be ignored under the condition of dead load.