The invention discloses cereal rice capable of improving the gastrointestinal function and a preparation method thereof and belongs to the technical field of grain deep processing. The cereal rice is prepared through the follow steps: with broken rice as a main raw material, ultrasonic cleaning, microwave curing, drying and sterilization are carried out on the broken rice, the processed broken rice, grain flour with a special flavor, enzymatic hydrolysate and other functional raw materials are subjected to pelleting, particle arrangement and microwave drying, so that the cereal rice is obtained, the tissue structure, granularity, hardness and viscosity of the cereal rice are similar to those of rice, the cereal rice can be cooked together with rice simultaneously, has a taste and chewiness which are similar to those of rice, is unique in flavor, soft in fragrance, strong in appetite, easy to digest, and rich and complete in nutrition, can improve immunity and disease resistance of human bodies, and improve the gastrointestinal function, and the quality guarantee period of the cereal rice is three times of that of the rice sold on the market. More importantly, a shortcut is developed for efficient value-added full utilization of broken rice, a road for deep processing of the broken rice is widened, the economic value of the broken rice is increased, better social benefits and economic benefits are realized and a road of sustainable development is explored for deep processing of agricultural byproducts and effective solving of three rural issues.