The present invention discloses a stapler, comprising an execution component and an instrument body on which the execution component is installed, the instrument body comprising a shell, a firing
handle pivotally connected to the shell, a rack, a rack
paddle and a rack
paddle baffle, the firing
handle is connected to the rack through the rack
paddle; the rack is an interval tooth shape, and is provided with an A tooth located at the extreme firing position of a first nail
magazine and a B tooth located at the extreme firing position of a second nail
magazine, there is no tooth structure between the A tooth and the B tooth, and the length of the first nail
magazine is smaller than that of the second nail magazine; the rack paddle baffle is slidably connected to the shell, and the greater the length of the nail magazine installed in the execution component, the farther the rack paddle baffle is from the rotation center of the firing
handle; therefore, it can be suitable for nail magazines of different specifications, and different firing distances can be set according to different nail magazine components, thereby solving the problem that a short-
stroke nail magazine can continue to fire after reaching the end of the
stroke, thereby avoiding damage to the instrument or additional harm to the patient.