The invention discloses a rotating mechanism capable of realizing limiting adjustment. The rotating mechanism comprises a rotating body and a supporting body, wherein the rotating body is connected with the supporting body through a roller wheel, an adjustment plate with a guide groove is arranged on the rotating body, a fixing column M is arranged in the guide groove, and the guide groove makes reciprocating motion around the fixing column M. The invention further provides a covering device comprising the rotating mechanism, and the covering device further comprises a belt with second through holes and a transmission mechanism mounted on a rack; the rotating body and the supporting body are a first box and a second box, respectively; the bottom surfaces and the side surfaces of the first box and the second box are closed; the belt surrounds vacuum cover boards on the surfaces of the first box and the second box, is annularly arranged, and is driven by the transmission mechanism to move; and covering boards are arranged on two sides of the second box. Compared with the prior art, the covering device has the advantages that the covering angle is adjustable, during the covering process, the transmission is stable, no deviation exists, no edge folding exists, no reverse folding exists, and the covering size is accurate.