Abstract: According to the principles of force method in structural mechanics,computational programs have been designed by C₊₊language for the models of plate-girder bridges with transverse rigid joints,thus realizing computer-aided design while considering transverse calculation of loads in bridge engineering design avoiding that the amounts of computational tables are consulted and the amounts of polynomials done.Without considering bending moments,the models above will be simplified into that of plate-girder bridge with transverse hinge joints,so the programs could be extended with more practicality.Finally,numerical examples are analysised by using the program and the results show th at all these are conrect and reliable,and it is easy to extend its functions and deal with the tasks of multi-objects because there are open connectors by applying multi-lines technology of the Windows^® system.