A method for producing a tea beverage with an oxygen content of ≤ 1 mg/L, characterized in that it consists of the following steps: 1) extracting tea leaves with reverse-osmosis water that is deoxygenated and deionized and has a temperature of 40-95°C and an oxygen content of ≤ 1 mg/L, wherein ≥ 99% nitrogen is injected from the top of the closed water tank containing the deoxygenized water, extraction of tea leaves is carried out in a closed extraction tank, high pure nitrogen is injected to replace air in the tank prior to extraction, and the whole extraction process is carried out under nitrogen protection, 2) filtrating or clearing the extraction liquid of the tea leaves by centrifugation and hop-pocket, wherein all the holding tanks used during filtration or clearing are closed tanks, ≥ 99% nitrogen is injected to replace air in each of the tanks in advance, and the whole process is carried out under nitrogen protection, 3) transferring the tea extraction liquid or clear liquor into a closed blending tank, diluting and blending it with the reverse-osmosis water that is deoxygenated and deionized, at a ratio of 1:1-10 by weight, and adding an antioxidant, wherein ≥ 99% nitrogen is injected to replace air in the blending tank in advance, and the whole process is carried out under nitrogen protection, 4) subjecting the blended tea extraction liquid or clear liquor having a dissolved oxygen content of ≤ 1 mg/L to ultra high temperature short time sterilization, wherein no degassing treatment is performed before sterilization, 5) subjecting the sterilized tea extraction liquid or clear liquor to aseptic cold filling by using PET plastic bottles to immediately get various tea beverages, wherein during aseptic cold filling, the bottle mouths are purged with nitrogen before capping the PET bottles, so as to reduce the oxygen content of the air in top gap of the bottles. 1) extracting tea leaves with reverse-osmosis water that is deoxygenated and deionized and has a temperature of 40-95°C and an oxygen content of ≤ 1 mg/L, wherein ≥ 99% nitrogen is injected from the top of the closed water tank containing the deoxygenized water, extraction of tea leaves is carried out in a closed extraction tank, high pure nitrogen is injected to replace air in the tank prior to extraction, and the whole extraction process is carried out under nitrogen protection, 2) filtrating or clearing the extraction liquid of the tea leaves by centrifugation and hop-pocket, wherein all the holding tanks used during filtration or clearing are closed tanks, ≥ 99% nitrogen is injected to replace air in each of the tanks in advance, and the whole process is carried out under nitrogen protection, 3) transferring the tea extraction liquid or clear liquor into a closed blending tank, diluting and blending it with the reverse-osmosis water that is deoxygenated and deionized, at a ratio of 1:1-10 by weight, and adding an antioxidant, wherein ≥ 99% nitrogen is injected to replace air in the blending tank in advance, and the whole process is carried out under nitrogen protection, 4) subjecting the blended tea extraction liquid or clear liquor having a dissolved oxygen content of ≤ 1 mg/L to ultra high temperature short time sterilization, wherein no degassing treatment is performed before sterilization, 5) subjecting the sterilized tea extraction liquid or clear liquor to aseptic cold filling by using PET plastic bottles to immediately get various tea beverages, wherein during aseptic cold filling, the bottle mouths are purged with nitrogen before capping the PET bottles, so as to reduce the oxygen content of the air in top gap of the bottles.