The invention discloses a two-stage-structure inerter with an adjustable inerter coefficient. The two-stage-structure inerter with the adjustable inerter coefficient comprises a hydraulic cylinder, aninertia force generator A, an inertia force generator B, an upper piston rod, a lower piston rod, a communicating pipeline and a blocking channel. Spiral grooves are formed in outer walls of the inertia force generator A and the inertia force generator B; a spiral groove rotating direction of the inertia force generator A is opposite to a spiral groove rotating direction of the inertia force generator B; and compared with a one-stage-structure inerter, according to the two-stage-structure inerter, through arranging the two upper and lower inertia force generators, the inertia force generatorA and the inertia force generator B are not connected directly, and when energy generated by the vibration of a vehicle wheel is provided to the inertia force generator B, the vibration is converted into energy for flowing of liquid in a lower cylinder, and the vibration of the vehicle wheel cannot be directly transmitted to a vehicle body through the inerter, so that the influence of the vibration of the vehicle wheel on the vehicle body can be greatly reduced.