Shoulder/satchel double-purpose bag

A shoulder/satchel double-purpose bag comprises a bag body, wherein the top parts of two side ends of the bag body are fixed with connecting pieces; the lower end of a shoulder belt or satchel belt penetrate through the ring of the connecting piece, then folded and superposed with the belt body; the shoulder belt body or satchel belt body is protruded with a convex cylinder; the convex cylinder comprises a connecting rod fixed at the belt body and a spherical limiting part that is arranged at the top end of the connecting rod in a protruding way and has the diameter larger than that of the connecting rod; a position at the lower end of the shoulder belt or the satchel belt, corresponding to the convex cylinder, is provided with a connecting hole for the convex cylinder to penetrate through, and the diameter of the connecting hole is matched with that of the connecting rod; as the shoulder belt or the satchel belt 2 realizes connection with the connecting piece by the convex cylinder penetrating through the co