The invention relates to a closed and clean method for fermenting vegetables with low-salt vegan lactic acid bacteria. The main steps are as follows: 1. Pretreatment of vegetables, stripping of vegetable outer layers or insects, soil dust, damage and other vegetable leaves, if necessary, leaves Washed vegetables need to be separated leaf by leaf in advance to facilitate the cleaning of dirt； 2. Pre-wash, tap water through a shower head pressurized water column (flowing water) to wash the vegetables to no dust and no obvious dirt； 3, second-degree cleaning The water after primary filtration, activated carbon dechlorination, and filtration through a micron filter is processed into clean water by a backwash microporous ultrafiltration (UF) membrane, and the vegetables are washed by a water column pressurized by a motor； 4. Place in fermentation Barrel treatment. Vegetables that have been washed twice in the third step are placed in a mesh bag element and placed in a fermentation barrel, and fermentation auxiliary materials are added. Fermented lactic acid bacteria culture medium must use "halal certified" yeast extract. , And "halal certified" pure plant-derived protein and other vegetarian sources as the nitrogen source of lactic acid bacteria, and the clean water of the previous step 3 is added as the fermentation broth, the water level is the height of the flooded vegetables, and a fixed pressure is placed on the mesh bag element And a regular shape weight is placed on the fixed platen； a top cover is combined with the opening on the top of the fermentation barrel, and the first cover and the second vent tube with one-way valves are respectively worn on the top cover. , The bottom end of the first aeration tube extends below the fermentation liquid surface； 5, filled with carbon dioxide, the carbon dioxide gas is filled from the first aeration tube set in the top cover into the fermentation barrel and driven under the fermentation liquid surface, lighter oxygen is D
