The invention discloses a preparation method of a protein mulberry health-care oral liquid. The preparation method comprises the following steps of S1, preparing the following raw materials in parts by weight of 60-65 parts of fresh protein mulberry leaves, 25-30 parts of aronia melanocarpa, 5-8 parts of radix astragali, 1-2 parts of a stabilizer, 0.1-0.2 part of protease and 280-325 parts of purified water; S2, putting the aronia melanocarpa into a freeze dryer, and preparing the aronia melanocarpa into aronia melanocarpa freeze-dried fruits; and then preparing a crusher, putting the freeze-dried aronia melanocarpa fruits into the crusher, and starting the crusher to crush the freeze-dried aronia melanocarpa fruits. The health-care oral liquid is reasonable in design, is prepared from protein mulberries and aronia melanocarpa which contain various components such as flavonoids, polysaccharides, alkaloids, phytosterols, volatile oil, amino acids, vitamins, trace elements and the like,and has the effects of reducing blood sugar, reducing blood fat, reducing blood pressure, resisting bacteria and viruses, resisting aging and the like; and the effects of preventing cardiovascular diseases, stopping sweating, returning superficies, tonifying the spleen and nourishing the stomach are achieved.