The invention provides a detoxifying and slimming mango enzyme and a preparation method thereof. The mango enzyme takes mangoes, siraitia grosvenorii, hemp kernels, bunge cherry seeds and almonds as main materials, cranberries, oranges and roselle as auxiliary materials, the beneficial ingredients are absorbed to be compounded, then cichorium intybus, cabbages, okra, celery, black beans, pineapples, lemons, grapes, tomatoes, green plums, apples, passion fruits, pitaya, guavas and litchi are mixed and broken to obtain a mixture as seasoning, the mixture is inoculated with mixed bacterial liquidfor fermentation, and then vegetable fat powder and food additives are added for mixing. The main materials, auxiliary materials, adjuvant materials and primers are combined together to prepare the enzyme which can moisten intestines and soften dry feces. After entering the intestines, the feces and toxins can be excreted from a body, the gastrointestinal function can be repaired and improved, metabolism can be improved, a human detoxification system can be activated, and the mango enzyme is a healthy detoxifying and slimming drink in line with the taste of the public.