A vibrating fat eliminating device includes a vibrating mainbody, a chair body and a positioning unit. The vibrating mainbody includes a fixing notch and an upper surface, wherein the fixing notch is disposed on the upper surface. The chair body is detachably disposed on the vibrating mainbody and includes a supporting frame and a cushion, wherein the supporting frame is disposed on the upper surface, the cushion is disposed on the supporting frame, and the supporting frame includes a connecting portion having a through hole. The positioning unit passes through the through hole and is connected to the fixing notch correspondingly, wherein the chair body is detachably disposed on the upper surface via the positioning unit.