A retraction device includes: a spindle, a support plate and a plurality of spring washers. The spindle is movable along an axis direction thereof and has a first end; a support plate has a fixed position, the first end of the spindle penetrates the support plate; and the plurality of spring washers are fitted over the first end of the spindle and stacked together in an identical direction. The plurality of spring washers are compressed between the spindle and the support plate with a predetermined pre-load. The spindle is configured to be switchable between a first position and a second position, and capable of moving a predetermined distance relative to the support plate in the axis direction of the spindle during switching. When in the first position, the spindle is farthest from the support plate, when in the second position, the spindle is closest to the support plate.