The invention relates to a composition absorbed in intestines and capable of relaxing bowel and expelling toxins. The composition comprises the following components in percentage by mass: 5-95 percent of superfine black fungus powder and 95-5 percent of coconut shell carbon. The invention also provides a preparation method and application of the composition. The composition has the advantages that after the black fungus is subjected to superfine grinding, water in the black fungus can be adsorbed by multiple times, so that the defecate is softened and is conveniently discharged, the coconut shell carbon is not absorbed in the intestines, enterotoxins can be adsorbed, the aim of expelling the toxins is achieved, the combined effects supplement each other, and an optimal effect can be achieved. An enteric coating is coated on the outer layer, so that the product exerts the effects in the intestines and is not damaged by a strongly acidic environment in the stomach, and the best effect is achieved. Moreover, the black fungus powder and coconut shell carbon are taken as raw materials, and the composition is safe in components and non-toxic and harmless to human body.