A manufacturing method of a low-calorie sol food material includes four steps. The first step includes stirring a mixture of water, glucomannan or konjac refined flour or a combination thereof, and a poorly-soluble water absorbent, whereby the mixture is swollen to form a sol substance. The second step includes kneading an alkaline agent into the sol substance to prepare a pH-adjusted sol substance. The third step includes heating the pH-adjusted sol substance under a temperature condition at 70 to 130° C. to make the pH-adjusted sol substance into a gelatinous substance. The fourth step includes cooling the gelatinous substance to a temperature range of 0 to 15° C. to make the gelatinous substance solate.
