This product is a special polyolefin as a substrate, containing special halogen-free flame retardants, smoke suppressants, etc., by a special recipe precision mixing process. It has excellent flame retardancy, resulting in very low smoke concentrations. It is suitable for large-size low-smoke halogen-free flame-retardant cables such as railway optical cables and power cables with a diameter of 20 mm or more laid in non-open-air occasions.