Fastening structure

1. A fastening structure, comprising a circular sleeve and a coupling member; one end of the circular sleeve being a connecting end, an end face of another end of the circular sleeve being recessed to form a receiving trough, a bottom of the receiving trough being provided with a first magnetic member, a wall of the receiving trough being provided with a protruding post; the coupling member having a cylindrical shape, a second magnetic member corresponding to the first magnetic member being disposed inside one end of the coupling member, the first magnetic member and the second magnetic member having repulsive magnetic poles, at least one guide groove being formed on an outer wall of the coupling member, one end of the guide groove being an open axial groove with an opening at an edge of the coupling member, another end of the guide groove being a closed axial groove, the closed axial groove having a stop end at its distal end thereof, the guide groove having a transverse groove between the open axial groove and the closed axial groove to communicate with the open axial groove and the closed axial groove; another end of the coupling member being a pivot end; wherein when the coupling member is to be fitted in the receiving trough, the protruding post is inserted in the guide groove from the opening of the open axial groove and passes through the transverse groove, through the first magnetic member and the second magnetic member to repel each other, the protruding post is locked to the stop end of the closed axial groove, wherein the pivot end of the coupling member is provided with a central passage extending inwardly, and the second magnetic member is disposed at a bottom of the central passage.