The invention discloses an automatic updating method for a three-dimensional model of an unmanned mining work face, and belongs to the field of updating of three-dimensional models of unmanned mining work faces of mines. According to the method, for a coal seam model in front of a work face, a parameterized control mesh subdivision model for a coal mining machine is established in a proper time, so that dynamic changes of coal mining scenes (such as long wall mining, short wall mining, top coal caving, room mining, room and pillar mining and the like) of various stope faces can be adapted; and the coal mining machine obtains change information of the work face and working parameters of the coal mining machine in a coal cutting process and finishes dynamic timely updating of the work face by utilizing an automatic texture mapping technology, local increment updating and boundary seaming through positioning a cutting point, moving the cutting point and calculating texture coordinates of the cutting point.