The invention discloses an anti-fatigue functional beverage and a preparation method thereof. The anti-fatigue functional beverage comprises the following components: ginseng juice, Chinese yam juice, oligosaccharide, taurine, inositol, lysine, nicotinamide, calcium pantothenate, caffeine, vitamin B6, vitamin B1, vitamin B12, sucrose, fructose, apple juice, citric acid, sodium citrate, fruit essence, sodium carboxymethyl cellulose, tartaric acid, green tea extract, zinc gluconate, potassium chloride, vitamin C and water. The preparation method comprises the steps of respectively mixing the raw materials, then adding water to enable the volume to be constant, evenly mixing, homogenizing, filtering, carrying out instantaneous high-temperature sterilization, canning, sealing and cooling. The drink has the functions of relieving physical fatigue and supplementing multiple nutrient elements, and is capable of supplementing water and electrolyte which are lost due to sweating of the human body after a great deal of sports and labor in time so as to enable the body fluid to be balanced.