The invention relates to a rice milk and a preparation method of the rice milk, in particular to an edible mushroom flavor nutrient rice milk and a preparation method of the edible mushroom flavor nutrient rice milk. The nutrient rice milk comprises the following raw materials in following parts by weight: 800 to 1200 parts of fried corn flour, 400 to 600 parts of fried rice flour, 400 to 600 parts of fried millet flour, and 24 to 320 parts of dried cordyceps militaris. The preparation method of the nutrient rice milk comprises the following steps of crushing the dried cordyceps militaris by a machine, sieving, uniformly mixing with water, treating by ultrasonic wave, hydrolyzing to obtain the cordyceps militaris hydrolyzate; compounding the fried corn flour, the fried rice flour and the fried millet flour to obtain the compound flour; mixing the cordyceps militaris hydrolyzate and the compound flour, granulating, drying by hot air, crushing and sieving. The nutrient rice milk provided by the invention has the advantages that the flavor is particular, the nutrition is complete, the healthcare effect is realized, various nutrient elements required in daily life can be provided for a human body, multiple types of bioactive matters can be provided, and the important function is realized for maintaining the health of the human body. The preparation method is simple, and is suitable for application and popularization.