The invention discloses maca ferment and a preparation method thereof. The method specifically includes the steps of firstly, stirring and mixing maca mixed fermentation raw materials to obtain a mixture; secondly, adding an enzyme activity keeping agent to the mixture; thirdly, adding bacterial liquid, and conducting sealing and fermenting; fourthly, conducting filtering. The maca mixed fermentation raw materials include, by weight, 5-15 parts of maca, 10-30 parts of apple, 10-20 parts of carrot, 5-15 parts of broccoli, 20-40 parts of shiitake and 10-20 parts of cucumber. The maca ferment contains multi-enzyme ferment, proteolysis ferment, lipolysis ferment and amylolysis ferment, contains macaenes, macamides, various natural vitamins, mineral substances, amino acid, trace elements and the like, can be used for enhancing vigor, adjusting reproduction and metabolism, promoting fertility, improving the sexual function, treating climacteric syndromes, climacteric syndromes and depression, increasing bone mineral density, treating anemia and resisting oxidation, and is a natural internal secretion adjustor. In addition, the ferment has effects on resisting cancer and leukemia and the like.