With the continuous increase of the operation speed of high-speed EMUs, the abnormal lateral vibration of the carbody problem continues to emerge, and the traditional passive suspension has a poor effect on the lateral vibration suppression of the carbody. This paper first established a two-degree-of-freedom theoretical model and designed algorithms with PID (Proportion Integration Differentiation) and the fractional-order PID (fra_PID) control algorithm as the core to control the damping force of dampers. Then the SIMPACK and SIMULINK are used to establish a co-simulation model of the second lateral damper control model of high-speed EMUs. Finally, the PID control algorithm and the fra_PID control algorithm variable damping suspension system are used to control the abnormal lateral vibration of the carbody, and the lateral vibration control effect of the vehicle in the tangent track, the curved track, the first hunting instability state, and second hunting instability state are studied. The results showed that the lateral vibration of the carbody is suppressed when the vehicle used the variable damping suspension system in the normal state and the hunting state. When in the first hunting instability state, the amplitude of the lateral acceleration of the carbody is decreased by 41% with the fra_PID control algorithm. When in the second hunting instability state, the amplitude of the lateral acceleration of the carbody is decreased by 17% with the fra_PID control algorithm. The PID controllable damping suspension system can provide a reference for suppressing abnormal vibration of the high-speed EMUs.