The reinforced concrete piles (RC) in integral abutment bridges (IAB) are challenging to meet the longitudinal deformation of bridges with significant lateral stiffness. This paper proposes a new form of pile comprised of UHPC and RC piles in series to meet the longitudinal deformation demand of IAB. Tests were conducted for two UHPC/RC segmental piles (with or without prestressing). The failure characteristics, hysteretic behavior curves, skeleton curves, equivalent viscous damping ratio, and rigidity degeneration were developed using horizontal displacement loads. The failure position of the non-prestressed segmental piles is at the buried depth of three times the diameter of the pile, the displacement of the pile top when the pile cracks is 8-10 mm; the failure position of the prestressed segmental piles is at the buried depth of four times the diameter of the pile, The displacement of the pile top when the pile cracks is 10-15 mm. The results show that prestressing can effectively improve the resistance cracking capacity of step piles and seismic properties, while meeting the deformation requirements of IAB. The finite element model (OpenSees) was used for modeling and analysis. The analysis results show that the horizontal bearing capacity and deformation capacity of stepped pile can be improved by the increase of prestress degree, the ratio of length and stiffness of pile.