The invention provides a gas-containing high protein whey transparent beverage and a preparation method thereof. The beverage comprises the following raw materials by weight percent: 0.5-6% of whey protein isolate, 0.001-18% of sweetening agent and the balance of water, wherein the sum of the weight percent of all the raw materials is 100%. The volume fraction of the CO2 gas introduced into the beverage is 5-40%. The preparation method thereof comprises the following steps: mixing the raw materials by weight percent, sterilizing, cooling, introducing CO2 gas and filling, thereby acquiring the beverage. The invention creatively provides the gas-containing high protein whey transparent beverage. The beverage is neutral, contains gas and is high in protein and free from fat; ultrahigh stability can be kept under the condition that no stabilizer is added; the beverage is transparent and tastes cool, sour, sweet and nice; the beverage can be smoothly industrially produced; and the current situation of the sports beverage being apotrophic in the present market can be filled up.