Rotary supporting device

The invention relates to a rotary supporting device which comprises two platform mechanisms, a rotating mechanism, a fixing mechanism, a supporting mechanism and a control unit, wherein the two platform mechanisms are arranged on the horizontal plane in parallel, each platform mechanism comprises a bottom plate and a guide rail structure, and one platform mechanism also comprises a first driving structure; the two ends of the rotating mechanism are connected to the guide rail structures on the two platform mechanisms respectively, and the rotating mechanism comprises a horizontal plate, two rotating disc structures and a second driving structure; the fixing mechanism is arranged in the center of the rotating mechanism and comprises two stand columns, a placing plate, two side pushing structures, a third driving structure and an ejection head; the supporting mechanism is connected to the lower surfaces of the bottom plates and comprises a fixing plate, a fourth driving structure, a lever structure and a suppor