Spindle Type Structure for Preventing Opposite Sliding Doors from Swaying

A spindle type structure includes a lower rail mounted in a longitudinal direction at a lower side of a vehicle body, a lower rail roller unit rollably connected to the lower rail, a lower rail swing arm rotatably connected to the lower rail roller unit and a door, a lower guide rail mounted on the door and configured to form a lower guide route in the longitudinal direction, and a spindle assembly positioned at one side of the lower rail, the spindle assembly including a spindle connected in the longitudinal direction to a fixing unit fixed to the vehicle body, having one end rollably connected to the lower guide rail, having a threaded portion formed on an outer circumferential surface thereof, and being configured to be movable in a threaded manner between the vehicle body and the door.