A machine tool system includes: a machine tool that includes an openable door configured to block an opening of a cover surrounding the machine tool, and a door driving unit configured to open and close the door; and a work exchange device configured to exchange a work disposed in the cover. Further, the machine tool system includes: a first opening width setting unit configured to set a door opening width of the door; a second opening width setting unit configured to set a turnback opening width; and a door control unit configured to control the door driving unit to move the door in an opening direction from a completely closed position of the door to a position of the turnback opening width of the door, then move the door in a closing direction and stop the door at a position of the door opening width.