The invention relates to a preparation method of a feed for preventing horse sudden death syndromes. The preparation method comprises the steps of crushing 10kg of phyllanthusreticulatus poir, 15kg of spinach, 10kg of heliotropium indicum, 5kg of table salt, 15kg of fructus aurantii immaturus, 60kg of bean pulp, 10kg of chamaenerion root, 30kg of wheat bran, 10kg of glucose, 20kg of cabbage, 15kg of bean oil, 10kg of dried ginger, 30kg of rice bran, 10kg of kudzu root, 10kg of lotus leaf, 60kg of yeast powder, 5kg of yellowflower toadlily herb, 10kg of albizia flower, 5kg of lysine, 5kg of threonine and 10kg of white peony root, screening through a 80-mesh screen, stirring in a feed stirring machine for 40 minutes, granulating in a ring die feed machine, drying, and packaging by bagging. The feed prepared by the method disclosed by the invention can prevent the horse sudden death syndromes very effectively.