Based on the OpenSees platform, a model of a concrete-filled steel tubular (CFST) arch bridge is analyzed, and then it is compared with the results of the Midas Civil model. Through the incremental dynamic analysis (IDA) under strong earthquake records, the transverse nonlinear seismic performance of the arch rib of the CFST arch bridge is discussed. The bending moment time history curves of the arch foot and the displacement time history curves of the vault are compared with those of two different arch rib models (elastic beam element and fiber beam element). The yield mechanisms of the key sections of the arch rib are analyzed, and their IDA curves and vault displacement are drawn. The results show that under strong ground motions, the arch foot and vault do not necessarily yield first, but the section-changing position or limped-mass connection of arch rib, which must be carefully considered in the design. With the increase in ground motion, the arch rib gradually yields, beginning with the bracings, and then the arch foot and vault, and then the whole arch rib. The arch rib has a good nonlinear performance and seismic capacity.