The invention provides a suspender testing fixture. The suspender testing fixture is characterized in that slidable detection arms are arranged on the suspender testing fixture; the slidable detection arms can be fixed by a slidable detection arm fixing mechanism at the corresponding position conforming to the detection size requirement for a detected suspender; and a detection end head on each slidable detection arm can be exchanged according to the shape and size of a support claw of the detected suspender, so that the suspender testing fixture can be suitable for multi series of suspenders for detecting support claw space change and/or support claw shape change for the detected suspender, so that the suspender testing fixture is wide in application. The suspender testing fixture includes an optimal scheme with four detection end heads, and can complete detection of the detected suspender by one time, and the detection process is simple and practicable.