The invention discloses a multi-stage anti-collision device for a circular-section pier or pillar. The device comprises a main pile casing, reserved gaps, viscous fluid, a secondary pile casing, bolts and a baffle. According to the multi-stage anti-collision device for the circular-section pier or pillar, by installing a novel energy dissipation device on the pier (pillar), when the pier (pillar) is under the effect of a strong impact load, the main pile casing bears the impact load firstly, and meanwhile, impact energy is dissipated through deformation, so that first-stage energy dissipation is achieved; for avoiding that the impact load is too large and thus beyond the resistance limit of the main pile casing, the main pile casing can rotate around the central axis of the pier (pillar), and the overlarge impact load can be transferred, so that second-stage energy dissipation is achieved; and while the main pile casing rotates, through energy dissipation of the viscous fluid between the main pile casing and secondary pile casing, third-stage energy dissipation is achieved, and the phenomenon that the concrete pillar is broken due to impacting is avoided. The multi-stage anti-collision device for the circular-section pier or pillar is used for preventing structural collapse caused when the pier (pillar) fails under the effect of the strong load; and the defects such as poor impact load resistance, low ductility, high building cost and large occupied space of a traditionally-used pier (pillar) strengthened with steel tubular shell are overcome.