The invention belongs to the technical field of food processing, and particularly relates to a making method of a sports beverage capable of eliminating free radicals. The making method comprises thefollowing steps of weighing edible bran powder, potassium dihydrogen phosphate and magnesium sulfate, performing uniform mixing, adding water, performing uniform stirring, performing sterilization, performing cooling, performing inoculation with aspergillus oryzae liquid seeds, performing uniform stirring to obtain a mixture, levelly laying the mixture on a pan, putting the pan in a climatic cabinate, and performing culturing so as to obtain aspergillus oryzae solid koji; adding sterile water to the aspergillus oryzae solid koji, performing uniform stirring, performing uniform stirring, and performing filtration so as to obtain mixed enzyme liquid and filter residues; adding clean water to the filter residues, performing uniform stirring, performing sterilization, performing cooling, performing inoculation with lactobacillus plantarum freeze-dried powder, performing anaerobic fermentation, then performing sterilization, performing cooling, adding mixed enzyme liquid, and performing enzymolysis so as to obtain enzymatic hydrolysate; and filtering the enzymatic hydrolysate, performing blending, performing filling, performing sealing, and performing sterilization so as to obtain finished products. After the sports beverage is drunk, too many free radicals generated in bodies of people after sports can be well eliminated, and damage of the free radicals to human bodies can be eliminated.