The invention discloses a functional composition with functions of controlling blood sugar and enhancing nutrition, which is prepared from main materials and a common carrier, wherein the main materials consist of functional sugars, composite vitamins, mineral substance, dietary fiber and high sweetener; and the functional sugars comprise L-arabinose and trehalose, the weight content of the L-arabinose is 10 to 80 percent, and the weight content of the trehalose is 10 to 50 percent. The functional composition uses two functional sugars as main sugar-reducing substances and is added with multiple composite vitamins, the mineral substance, the dietary fiber and the high sweetener, so the invention provides the functional composition with convenient use, good mouthfeel, safety, effectiveness and practicability of controlling blood sugar and enhancing nutrition for diabetes patients. The functional composition can well supplement nutrient substances required for the human body when the diabetes patients can feel relieved to enjoy a proper amount of sweet food.