The invention discloses a low-smoke halogen-free flame-retardant polyolefin cable material and a preparation method thereof. The formula of the cable material comprises the following raw materials in percentage by weight: 20-30% of ethylene-vinyl acetate copolymer, 10-20% of linear low-density polyethylene, 3-6% of compatilizer, 50-60% of inorganic flame retardant, 2-5% of synergistic flame retardant, 0.5-1% of coupling agent, 0.2-0.5% of lubricant and 0.2-0.5% of antioxidant. The preparation method of the cable material comprises surface treatment of the inorganic flame retardant, burdening,mixing, milling, extrusion and granulation and other process steps. Compared with the prior art, the cable material disclosed by the invention has the advantages of superior flame retardancy, low smoke, low toxicity, no droplets, good processing performance, good dispersion of the inorganic flame retardant, and better uniformity and surface finish degree.