V纶 cable conduit with polished inner surface and inner coating is enhanced through improved material mixing and production processes, which increases the smoothness of the conduit's inner wall, reducing friction resistance. The coefficient of friction is less than 0.3, significantly lower than other types of cable conduits, allowing the cable pull length to be extended to 100-130 meters during wiring, minimizing the need for manholes, lowering construction costs, and reducing labor intensity. Inner polishing involves using high-speed polishing equipment to create a dense, smooth surface on the rigid inner wall of the conduit. Inner coating is achieved by applying a layer of graphite emulsion lubricant evenly over the inner wall of the conduit using a film coating machine. This technology is widely used in underground cable projects internationally.