The invention relates to a preparation method of a quinoa flesh beverage, and belongs to the technical field of food processing. The preparation method concretely comprises the following working procedures: carefully choosing quinoa, soaking the chosen quinoa, cleaning the soaked quinoa, drying the cleaned quinoa, ageing the dried quinoa, putting the aged quinoa into a pulping machine, pulping the quinoa in the pulping machine so as to obtain quinoa serosity, taking 50% of the quinoa serosity, and adding the taken quinoa serosity into blended fruit liquid so as to obtain a solution; degassing the solution, homogenizing the degassed solution, and sterilizing the homogenized solution so as to obtain the quinoa flavored flesh beverage. The quinoa flesh beverage disclosed by the invention conforms to the requirements of people for safety, health, nutrition and nature of foods, not only has the unique flavor of the quinoa and the nutrition of apples, but also is ready-to-eat, convenient, diversified in taste, and suitable for large-scale industrial production; the processing links of the quinoa are reduced, and the quality and the nutrition of the quinoa can be maintained to the maximum extent. The preparation method disclosed by the invention is simple in working procedures, the produced quinoa flesh beverage has the fragrance of the quinoa, is delicious, ready-to-eat, convenient, and suitable for common people to consume, and can become popular fashionable healthy beverages.