A design of dual-polarized 3-D pattern manipulation structure (DP 3-D PMS) using slotline-based elements is presented for future 6G wireless networks. Firstly, the 3-D slotline element with variable slotline length is analyzed. Using this type of element, a single-polarized PMS is realized to control the reflected wave. Then, the expansion of dual-polarized PMS is obtained by utilizing dual-polarized elements with slotline pairs. Finally, calculations and simulations agree well with each other, showing that the proposed DP 3-D PMS possesses the ability to effectively manipulate the reflected wave within an angle range of 45°.