Quick-changing fixing knife

The invention discloses a quick-changing fixing knife and belongs to manual tools. A structure, for achieving the purpose of rapidly changing blades, of an existing manual knife is relatively complex. According to the quick-changing fixing knife, a knife handle is provided with a knife rest which is limited to the part between an unfolded position and a folded position to swing. The front portion of the knife rest is provided with a blade placement position, and the rear portion of the knife rest is provided with a blade changer. When the knife rest is located at the unfolded position, the blade placement position is rotated out of the knife handle from the web portion of the knife handle, and the blade changer is rotated out of the knife handle from the back portion of the knife handle. When the knife rest is located at the folded position, the blade placement position and the blade changer are stored into the knife handle. When a blade needs to be changed, the blade placement position and the blade changer