Telescopic binder

The utility model relates to a book binding machine, in particular to a telescopic binder, which comprises a base and a staple storage bin connected onto the base. The telescopic binder is characterized in that the base is slidably connected to the lower surface of a lower sliding plate through a slide groove, the staple storage bin is slidably connected to the upper surface of an upper sliding plate through a slide groove, and the lower sliding plate is hinged with the upper sliding plate integrally through a hinged shaft. Because positions of the staple storage bin and the base can be telescopic, the telescopic binder can adjust binding positions according to needs, is convenient in use and expands application range.