The invention discloses a perfluorocarbon reflective w-beam guardrail and a preparation method thereof. The w-beam guardrail is coated with a perfluorocarbon reflective paint layer with the thickness being 20-80 microns. During preparation, firstly, the w-beam guardrail is polished, cleaned, deoiled and subjected to dirt removal; then, a prime coating layer is sprayed; finally, the prime coating layer is coated with the perfluorocarbon reflective paint layer with the thickness being 20-80 microns. The w-beam guardrail has the advantages that the sun-proof performance and weather resistance are excellent, and the guardrail can resist photocorrosion of ultraviolet rays and is not prone to fading and extremely high in aging resistance; the w-beam guardrail is good in stain resistance and scouring resistance, has a self-cleaning function and can protect reflection performance more effectively; the w-beam guardrail is high in adhesion, excellent in acid and alkali resistance and better to use in areas, with serious acid precipitation, in Szechwan; the guardrail can be combined with various materials and is wide in application range and good in wear resistance and scratching performance.