The invention discloses a method for preparing ready-to-eat rice based on a twin-screw extruder. The method comprises the specific steps of treating raw materials, performing extrusion and curing, performing low temperature drying on porridge rice, preparing auxiliary materials, mixing raw materials and performing aseptic packaging. Through grinding, re-combination and granulation of five-cereal raw materials, the porridge rice of which the appearance is similar with that of rice granules is produced; and besides, rice flour after gelatinizing treatment is used as a thickening auxiliary material of the ready-to-eat rice, so that the formed ready-to-eat rice finished products are ready-to-eat rice finished products which are dried and resistant to store and can dissolve quickly. When beingeaten, the ready-to-eat rice finished products only need to be put in tableware, and boiled water of 50-100 DEG C is added for brewing the ready-to-eat rice finished products; and besides, the brewedready-to-eat rice has favorable appearance and mouth feel. In addition, compared with a traditional ready-to-eat rice production technology, the method disclosed by the invention has a higher technique doorsill, and imitation by an illegal workshop being deficient in technique level can be avoided.