Stretchable stapler

The utility model discloses a stretchable stapler, which comprises chain rivets, a chain rivet sliding block, a chain rivet offset spring, a positioning spring wall, a return spring, a working press plate and a stretchable chute arranged in a shell. Stretchable arms comprise an upper stretchable arm and a lower stretchable arm; the tail ends of the upper stretchable arm and the lower stretchable arm are movably linked by a round pin; long sides of the stretchable arms are positioned on the same plane; narrow sides of the stretchable arms are waved; the long sides are provided with positioning grooves; a positioning pin is arranged at the tail of the shell; and the stretchable arms on the upper layer and the lower layer can be stretched in time by the return spring.