Auxiliary focusing device

The utility model provides an auxiliary focusing device which is applied to a laser marking machine with a marking head, and the auxiliary focusing device comprises a mounting seat which is connected with the marking head and is provided with a mounting surface; the two linear light sources are perpendicularly arranged on the mounting surface of the mounting base, light beams emitted by the two linear light sources are perpendicular and intersect to form an intersection point, and the intersection point is a laser focus of the laser marking machine; the rotating assembly is movably arranged on the mounting surface of the mounting seat; the point light source is connected with the rotating assembly and used for emitting light spots, the color of the light spots is different from that of the intersection point, and the rotating assembly is used for driving the point light source to rotate around the marking head so that the light spots can rotate around the intersection point when not coinciding with the inters