A mounting and dismounting device for cylindrical bodies comprises a fixing element, a moving element, and a buckling element. The fixing element connects to the moving element on both sides to form a hole. The cylindrical body is then inserted into the hole. A buckling part of the buckling element pivotally connects to the fixing element. One lifts a lifting part for the buckling element to urge against the cylindrical body in the hole. By lifting the lifting part, the cylindrical body can be mounted or dismounted.