Directional Textured Dysprosium foils were produced by rapid solidification and sequential cold rolling, and the influence of thickness and magnetic structure of Dysprosium foils on magnetic properties were analyzed and studied. The results show that magnetic properties of cold-rolled Dysprosium foils are better than rapid solidification Dysprosium foils, and the magnetization and permeability of the cold-rolled Dysprosium foils are related to the thickness and temperature. Below curie temperature, the cold-rolled Dysprosium foils has obvious soft magnetic properties, from 77 K to 4.2 K, the saturation magnetization of cold-rolled Dysprosium foils increases by 5-8 %, and the saturation magnetization of cold-rolled Dysprosium foils with 0.15 mm thickness reached 2880 kA/m at 4.2 K, and the maximum permeability of cold-rolled Dysprosium foils with 0.10 mm thickness approaches 30. Cryogenic magnetization of cold-rolled Dysprosium foils with a strong external magnetic field is higher than conventional Co-V-Fe below 85 K. Cryogenic magnetic properties of textured Dysprosium foils are related to the oxygen content and the orientation degree of (0001) crystal plane. The study laid the foundation of technology and principle for preparation of chunky directional textured Dysprosium soft magnet for cryogenic undulator