The invention discloses a connecting piece. The connecting piece comprises a pipe part, a bottom part, an opening, two elastic arms and two pin holes, wherein the bottom part is arranged at one end ofthe pipe part, the opening is positioned at the other end of the pipe part, the two elastic arms extend from the bottom part to the opening at intervals, a preset distance is reserved between each elastic arm and an inner wall of the pipe part, and the two pin holes are respectively arranged on the two elastic arms. The connecting piece is advantaged in that the connecting piece can be coupled with a rotating force receiving piece, so the rotating force receiving piece can freely deflect in a preset angle range relative to the connecting piece and cannot be separated from the connecting piece, and the connecting piece is simple in structure, quick to manufacture and capable of shortening the time required for being assembled with the rotating force receiving piece.