Dynamic axial compression technology, known as DAC, is a widely recognized technology that can maintain good separation effect in various sizes of column chromatography, and is also the best column packing technology in the field of preparative chromatography. When the user needs to load the preparation column with the inner diameter of more than 100mm, the general axial compression technology cannot meet the high separation requirements, and only dynamic axial compression technology can be used. Dynamic axial compression technology is the only one that can maintain good separation effect in column chromatography of various scales.