The present invention discloses a sugar-free and high calcium nutritional rice flour and a preparation method thereof. Raw materials of the sugar-free and high calcium nutritional rice include brown rice, germinated rice, tartarian buckwheat, corn, soy protein, wheat bran, coix seed, pumpkin powder, lotus root powder, calcium nutrition powder, sesame seeds, porphyra, kelp, dietary fiber, vegetable oil and sugar alcohols, wherein the calcium nutrition powder is prepared by uniformly mixing the following materials in parts by weight: cassava starch, biological calcium carbonate, sustained release maltodextrin, magnesium stearate, vitamin C and vitamin D. The sugar-free and high calcium nutritional rice flour is rich in nutrition and balance in energy; the sugar-free and high calcium nutritional rice flour not only has effects of delaying carbohydrate absorption, inhibiting blood sugar rise and treating diabetes, but also has rich calcium nutrition and is conducive to the absorption of calcium; meanwhile, the preparation method of the rice flour is simple and the production cycle is short.