Axial displacement compensation mechanism and vibration test device

The utility model relates to the technical field of vibration test stands, in particular to an axial displacement compensation mechanism and a vibration test device. The axial displacement compensation mechanism comprises a box body, a transmission shaft and a spline shaft, and the box body can be installed on the vibration table so that the box body and the vibration table can vibrate synchronously. The transmission shaft is rotatably arranged in the box body and can synchronously vibrate along the axial direction of the box body. One end of the transmission shaft is provided with an internal spline; one end of the spline shaft is provided with an external spline meshed with the internal spline, and the other end can be in transmission connection with the driving piece. And the spline shaft penetrates through the box body and is in transmission connection with the transmission shaft through spline meshing. According to the vibration test device, axial displacement compensation is realized through the axial d