A surgical purse-string suturing instrument comprises an upper jaw, jaw handle, grip, and a lower jaw, jaw handle, grip, wherein the jaws (1) and the corresponding jaw handles (3) are arranged in shape of “L” so that the doctor is able to clearly observe the placement of the tissues on the jaws (1) directly from one side of the jaw handle (3); in order to adapt to tissues of different widths, gaps (7), peaks (8) and valleys (9), or alternately arranged teeth (10) are disposed on the surfaces of the staple cartridges (2); by employing limiting rods (11) and anti-exceeding boss (13), the exceeding of tissues during the process of purse-string suturing can be effectively prevented so that the sutured purse-string has a complete shape.