The invention discloses a preserved sweet potato immersing liquid and a preparation method thereof, and belongs to the technical field of food processing. The preserved sweet potato immersing liquid comprises the following raw materials: red dates, Chinese wolfberry fruits, radix codonopsis, radix paeoniae alba, fructus aurantii immaturus, zizania aquatica, dried orange peel, hawthorn fruits, oyster mushrooms, a celery extract, vitamins, and trace elements. The preserved sweet potato immersing liquid is prepared by the following steps of preparing a mixed solution A, preparing a celery extract, preparing an immersing liquid, and so on. Being used in preparation processes of sweet potatoes, the prepared preserved sweet potato immersing liquid is capable of ensuring golden and transparent appearance, good elasticity, fine tenacity, sour-sweet and tasty flavor, chewy but loose taste, as well as unique aroma of fresh sweet potatoes and refreshing fragrance of celery of the prepared preserved sweet potatoes; moreover, the preserved sweet potatoes is adequate in fiber content and high in nutritional value. The preserved sweet potatoes are especially suitable for female consumption, and has the function of slimming; moreover, the preserved sweet potatoes are not high in sugar content, and the sugar is mainly composed of xylitol and maltose, and thus, the preserved sweet potatoes are also very suitable for people with hypertension and high cholesterol to eat. The High preserved sweet potatoes have very high promotion values.