The invention provides a processing method of a black garlic sauce prepared by mixing black garlic, water and other auxiliary materials together in proportion. The processing method is characterized in that the black garlic sauce is prepared through the processes of a, selecting 10-90 parts of black garlic, adding 1-50 parts of water and 1-80 parts of auxiliary materials, pulping, and uniformly stirring; b, sterilizing and packaging the uniformly-stirred sauce to obtain the black garlic sauce, wherein the auxiliary materials comprise one or more of oil, salt, sugar, honey, cooking wine, chili powder, fruit jam and vegetable sauce; the sterilization process is one of heating sterilization, microwave sterilization and pressure sterilization. The processing method provided by the invention has the effects and characteristics as follows: the black garlic sauce is rich in nutrition, simple in manufacturing process and strong in adjustability; the black garlic sauce is unique in flavor and is suitable for eating by people of all ages.