The invention relates to the field of polyethylene, and discloses a high-density polyethylene composition used for a cable sheathing material and a preparation method of a high-density polyethylene cable sheathing material. The composition comprises base resin; and the composition is characterized in that the base resin includes high-density polyethylene, and the high-density polyethylene has a melt flow rate of 0.2-0.8 g/10 min and a density of 0.94-0.96 g/cm<3>. The method provided by the invention can prepare the cable sheathing material having excellent properties by controlling the melt flow rate and density of the base resin high-density polyethylene in a specific range, preferably using the above high-density polyethylene together with carbon black masterbatch, and reduce the usageamount of an auxiliary agent, and the product has good stability.