The invention discloses a rotary motion mechanism of a three-dimensional drag chain. The rotary motion mechanism comprises a support bottom plate, a pneumatic telescopic mechanism and a sliding mechanism; the sliding mechanism is installed on the support bottom plate and can horizontally move on the support bottom plate in one direction under the action of the pneumatic telescopic mechanism; the sliding mechanism comprises a sliding plate, the bottom of the sliding plate is connected with the pneumatic telescopic mechanism, and the pneumatic telescopic mechanism drives the sliding plate to slide on the support bottom plate; the sliding plate is further provided with a tray used for bearing the drag chain, and the drag chain is wound on a rotating wheel arranged on the sliding plate; and the rotating wheel is rotationally connected with the sliding plate and can move integrally along with the sliding plate. According to the rotary motion mechanism, the rotary movement mechanism of the three-dimensional drag chain is simple in structure, convenient to install and operate and capable of simultaneously realizing rotation and axial movement of the drag chain, so that the movement of thedrag chain is more flexible and free, the movement adaptability to machine equipment is good, and the drag chain has good use value and practicability.