Abstract: A braking device includes a wheel frame plate assembly, a first connecting member connected to the wheel frame plate assembly, and an electromagnet assembly. The wheel frame plate includes a wheel frame plate and a wheel, one side of the wheel frame plate along a first direction is connected to the wheel, and the wheel is rotatable and adapted to be disposed above a braking plate. The electromagnet assembly includes an electromagnet connected to the wheel frame plate and being rotatable around a radial direction of the first connecting member, and the electromagnet and the wheel is located on the same side of the wheel frame plate along the first direction. The electromagnet is adapted to be attracted to or separated from the braking plate by moving along an axial direction of the first connecting member.