NOVELTY - Preparing high-salt liquid state sauce by fermenting continuous propionic acid content of short-chain fatty acid, comprises: (1) carrying out anaerobic fermentation of the sludge, kitchen garbage and alkali; (2) discharging part of the fermented mixture from anaerobic fermentation reactor, and then adding fresh sludge, kitchen garbage and alkali; (3) discharging the mixture, centrifuging, hydrolyzing and fermenting; (4) seed culture solution preparation Propionibacterium, and adding water to the anaerobic fermentation tank to ferment producing propionic acid.    USE - The method is useful for preparing high-salt liquid state sauce by fermenting continuous propionic acid content of short-chain fatty acid (claimed).    ADVANTAGE - The method is environment friendly.    DETAILED DESCRIPTION - Preparing high-salt liquid state sauce by fermenting continuous propionic acid content of short-chain fatty acid, comprises: (1) carrying out anaerobic fermentation of the sludge, kitchen garbage and alkali; (2) every period of time discharge part of the fermented mixture from anaerobic fermentation reactor, and then adding fresh sludge, kitchen garbage and alkali; (3) discharging the mixture of centrifuging, taking a certain amount of centrifuging the lower layer solid material are added to water in the suspension oscillator mixed with the fresh sludge in the step (2), kitchen garbage and alkali together into hydrolyzing and fermenting tank to the anaerobic, the centrifugal clear liquid to the sterilizing furnace sterilizing, cooling to the room temperature, pH of the sewage is adjusted to 6-8, and injected into the anaerobic fermentation tank; (4) seed culture solution preparation Propionibacterium, and adding water to the anaerobic fermentation tank to ferment producing propionic acid; (5) every period of time in the acid fermentation tank from anaerobic fermentation liquid discharging part, obtaining fermentation clear liquid rich in propionic acid by centrifuging, where at the same time for producing acid zymolytic tank to the anaerobic the centrifugal clear liquid adding sterilizing cleaned and Propionibacterium seed culture solution.