The invention discloses a reversing mechanism of an anchor chain and a mooring chain. The reversing mechanism comprises a base and a disk structure arranged on the base. The reversing mechanism further comprises a center plate, a tapered roller bearing I, a round nut, a bearing sleeve, a shaft, a tapered roller bearing II, a shaft sleeve II, a sealing ring, a baffle I and a baffle II. The base comprises adjusting screws, adjusting nuts, a fixing plate I, two fixing plates II and two fixing plates III. The disk structure comprises a base disk, a top disk, a bearing end cap, a shaft sleeve I, hanging rings, a cover plate and a screw. The reversing mechanism of the anchor chain and the mooring chain are simple in structure, reliable in performance, low in cost, stable in working operation, long in service life and convenient to install and maintain.