The invention discloses anti-cancer sea cucumber sugar-reducing flour and a preparation method, and relates to edible flour and a preparation method thereof. The flour is prepared by mixing sea cucumber, blueberry, purple rice, purple cabbage, black medlar, dry kelp, ganoderma lucidum, complete naked oat, cassia seed, balsam pear seed, white kidney bean, mung bean, soybean, pea, sword bean, Job's tears, white fungus, corn, green tea, black fungus, lentinula edodes and corn stigma. The anti-cancer sea cucumber sugar-reducing flour is reasonable in compatibility, can be used for meeting the requirement for nutrition and preventing blood sugar from being quickly raised after being eaten, is beneficial to glucose metabolism so as to inhibit complications, and has an effect of preventing multiple diseases such as cancer and coronary heart disease. The flour has the effects of resisting tumors and irradiation, delaying senescence, strengthening physique, regulating the body immunity, resisting fatigue, improving sleeping, improving memory, regulating blood sugar and blood fat, promoting growth and development, improving the osteoporosis, invigorating and tonifying kidney, nourishing yin and blood, tonifying yin and yang, promoting intelligence, developing brain, maintaining beauty, keeping young and the like.