Provided is a device of automatic mechanical wound opener for head and neck surgery. The device includes a wound opener including: a fixed unit and a plurality of drawing units, and at least one of the drawing units being movably connected on the fixed unit, wherein each of the drawing units includes a first arm, a second arm, and a blade connected to the second arm; wherein the first arm is connected to the fixed unit by one end thereof and to the second arm by the other end thereof; the second arm can be adjusted to an needed included angle relative to the first arm; and at least one of the blades includes an extension plate connected to an end of a plate part of the blade, and the extension plate is connected to the second arm for shortening the spacing between two blades.