Abstract: In order to estimate seismic performance of RC (reinforced concrete) bridge piers with hollow sections under composite earthquake loads, quasi-static testing was carried out on three RC rectangular hollow bridge piers under bidirectional cyclic load with a spiral shape loading protocol. Using finite element numerical analysis, the lateral displacement-force curves and curvature-moment curves of specimens were studied. The parameters considered were axial-compression ratio, wall thickness, and bi-axial bending strength ratio. By analyzing the effect of these parameters on the hysteretic behaviors of specimens, failure characteristics, and section performance, a new lateral displacement-force hysteretic curve model under bidirectional cyclic load with a spiral shape loading protocol was proposed. In the new hysteretic model, the coupling effect on strength, stiffness, and displacement under lateral bidirectional load was referenced. Then the proposed model was further used to obtain calculated lateral displacement-force curves, which agree well with experimental results.