The invention discloses an axle box loading butting device for an instrumented wheelset calibration test bench, and belongs to the field of the axle box loading positioning device at the end of the wheelset for instrumented wheelset calibration test. The device comprises a seat plate cross beam, a lower spring seat connecting rod and an upper spring seat connecting rod. The lower spring seat connecting rod is parallel to the upper spring seat connecting rod, and both are vertically fixed to the lower end face of the seat plate cross beam. The device is designed for the special structure of anaxle box. The height difference between the upper spring seat connecting rod and the lower spring seat connecting rod is exactly the same as the height difference between the upper end faces of both an upper spring seat and a lower spring seat of the axle box, and the spacing value between the upper spring seat connecting rod and the lower spring seat connecting rod arranged in parallel on the seat plate cross beam is exactly equal to the spacing value between axes of the upper spring seat and the lower spring seat of the axle box. A double-end stud connecting rod, a spring seat sealing ring cover, and a spring seat sealing end cover which are coaxially matched and fixedly connected with the counter bore structure on the spring seat of the axle box are arranged at both the upper spring seat connecting rod and lower spring seat connecting rod. Therefore, the reliable connection of the axle box on the instrumented wheelset calibration test bench can be achieved.