Black tea milk tea with high LAB value and preparation method thereof

The invention provides black tea milk tea with a high LAB value and a preparation method thereof, and the preparation method comprises the following steps: carrying out three-stage extraction on black tea by using deoxygenated water, collecting an extract liquid, and carrying out nitrogen sealing to obtain tea juice; the preparation method comprises the following steps: uniformly stirring vegetable oil, an emulsifier, vitamin E and water to obtain a mixed solution, uniformly mixing the mixed solution with milk powder, a sugar raw material and buffer salt, filtering, and homogenizing to obtain the milk, and mixing the tea juice with D-sodium erythorbate and sodium bicarbonate, uniformly stirring, adding the milk, uniformly stirring, filtering, homogenizing, deoxidizing, canning and sterilizing to obtain the tea milk. According to the preparation method provided by the invention, the problem that the color and luster of the instant milk tea are darkened due to Maillard reaction, grease deterioration or oxidatio