The invention relates to a Tianshan yacon granule and a preparation method thereof. The main raw materials contain Tianshan yacon, bitter gourd and guava. The preparation method comprises the following steps: crushing and mixing the raw materials, juicing, filtering to obtain clear liquid, concentrating and extracting the clear liquid to obtain paste, adding corn starch and water-soluble starch in the paste, and automatically spraying with a spray drier to obtain the granule. As bitter gourd and guava are added in the granule on the basis of the main raw material Tianshan yacon, the functionsand effects of the three raw materials can be complemented and the prepared granule has the effects of alleviating water retention, promoting appetite, clearing heat and detoxicating, thus the comprehensive health care and treatment effect of Tianshan yacon can be increased, the granule has more obvious treatment effect on the patients with hyperlipidemia, hypercholesterolemia and diabete and hasalso the effects of promoting the metabolism, regulating the gastrointestinal tract, clearing fire, detoxifying, preventing and curing acne and increasing the human immunity on common people. The formulation does not contain sucrose, belongs to the nuisanceless green health care product and is convenient to take.