The 3d dynamic focusing system mainly consists of XY galvo, dynamic focusing module, control card and upper computer software. By changing the position of the dynamic focusing mirror, its focus is still on the surface of the workpiece, so as to achieve the effect of the same diameter and small diameter of all the spots in the marking range. As a kind of galvo scanner head, mainly used in electronic communication, auto parts, precision hardware, instruments and meters, shoe materials, clothing, handicrafts, packaging, furniture, architectural models and other industries.