Onion fermentation method by virtue of added tetragenococcus halophilus

The invention provides an onion fermentation method by virtue of added tetragenococcus halophilus. A technological process comprises the following steps: peeling and removing bulbs of onions; washing and crushing; fermenting in a fermentation tank; centrifuging and filtering; and storing. The onion fermentation method comprises the specific steps as follows: (1) peeling and removing the bulbs and roots of onions, washing and crushing; (2) adding NaCl and an onion fermented product of the previous batch to the crushed materials, and inoculating with tetragenococcus halophilus; (3) fermenting the crushed onions into a constant-temperature box at 30-35 DEG C; (4) centrifuging and filtering the fermented product to obtain onion fermenting juice; and (5) adding beta-cyclodextrine into the onion fermenting juice and storing at a room temperature for later use. The onion fermentation method takes the onions as fermentation substrates which are fermented by using microorganisms in the environment at a room temperature for three to four days; the original spicy flavor of the onions is removed, the onion flavor is kept and the nutritional ingredients are improved; and the onion fermentation method is simple to operate in easily-controlled conditions and is suitable for large-scale production.