U-shaped high-strength aluminum alloy, embedded stainless steel guide rail and base are integrally ground and formed. The guide rail groove adopts 2 rows of Gothic structure design with 45° contact angle, providing equal load capacity in four directions, through appropriate steel ball pre-tightening force High precision and high rigidity can be achieved. In addition, the product adopts a fully-sealed design, with a low amount of dust generated during operation, and the overall dust-free level requirements can be achieved.