The invention provides new application of eucommia ulmoides leaf chlorogenic acid and a combination, belongs to the field of biological medicine, particularly relates to the poisonousness reducing effect of eucommia ulmoides leaf chlorogenic acid on bamboo leaf polysaccharide, and particularly provides application of eucommia ulmoides leaf chlorogenic acid in preparing medicine for reducing the poisonousness of the bamboo leaf polysaccharide. The invention further provides the combination. The combination comprises the eucommia ulmoides leaf chlorogenic acid and the bamboo leaf polysaccharide. The ratio of the mass of the eucommia ulmoides leaf chlorogenic acid and to the mass of the bamboo leaf polysaccharide is 1 to 0.5-5.