The invention discloses blueberry collagen polypeptide Ca yogurt and a preparation method thereof. The blueberry collagen polypeptide Ca yogurt is prepared from the following components in parts by weight: 5-10 parts of blueberry juice, 1-5 parts of blueberry flesh, 1-5 parts of collagen peptide Ca protein powder, 1-5 parts of grosvenor momordica concentrated juice, 0.5-1 part of a thickener, 0.05-1 part of starter culture and the balance of fresh milk. According to the blueberry collagen polypeptide Ca yogurt disclosed by the invention, by virtue of a sterilization method which has small influences on chemical components of the blueberry juice and the blueberry flesh, the blueberry juice and the blueberry flesh are added into the yogurt, the taste of the yogurt is improved, purple color is increased, and the blueberry juice and the blueberry flesh are also rich in anthocyanin serving as an antioxidant; the oligo-peptide collagen peptide Ca protein powder prepared from fish scales of tilapia has the digestion and absorption performance better than that of protein, also has the functions of promoting immunity, regulating hormone, resisting bacteria and viruses, reducing blood pressure and blood fat and the like and contains Ca element which is generally lacked by adolescents in the growth process; by virtue of combination of the yogurt, the blueberry juice, the blueberry flesh and the small molecular collagen peptide Ca protein powder, the blueberry collagen polypeptide Ca yogurt is good in taste and has a good health function.