The invention discloses a high-speed 
train secondary suspension semi-
automatic control device. The device comprises an 
air spring mechanism and a control device mechanism; the control mechanism comprises a 
coupling assembly, a cylinder body 
assembly and a fixing base; the cylinder body 
assembly comprises a cylinder 
barrel, the interior of the cylinder 
barrel is filled with 
magnetorheological fluid, and the interior of the cylinder 
barrel is sequentially provided with a 
piston rod I, a cylinder cover, a damping 
piston I, a damping 
piston II, a damping inner cylinder sleeve, a 
piston rod II anda cylinder bottom cover from top to bottom; the damping inner cylinder sleeve is a 
blind hole sleeve structure with an open upper end and a closed lower end, and an 
excitation coil is arranged on theouter cylindrical surface of the damping inner cylinder sleeve in the circumferential direction; and the damping piston II which is in clearance fit with the inner 
diameter dimension of the damping inner cylinder sleeve is arranged in the damping inner cylinder sleeve, and an 
excitation coil is arranged on the outer cylindrical surface of the damping piston II in the circumferential direction. According to the device, the opening degree of a throttling hole of an 
air spring system can be adaptively adjusted, the structure complexity is reduced on the premise of improving the adaptability of atrain to different operating conditions, and then the manufacturing cost is reduced.