The invention discloses a high-ester catechin capsule and a preparing method thereof, in particular to the high-ester catechin capsule for curing breast cancer and the preparing method thereof. The invention is made by applying the high-ester catechin and trichosanthes extractive as the main components and adding supplementary materials which are acceptable on the pharmacy. The method comprises the steps that: the trichosanthes is crushed, added with ethanol with 4 to 6 times of the volume of the trichosanthes to conduct recycling extraction for 2 to 4 hours and filtered, the ethanol extractive liquid is distilled in decompression to the one third to one fourth of the original volume, added with the supplementary materials and the high-ester catechin and evenly mixed to produce soft material, the grains is made by sieving a 14-mesh nylon sieve and dried under 65 to 70 DEG C till the water content is below 3percent, the dried grains is packed in an empty capsule to acquire the high-ester catechin capsule. The invention can be applicable for curing or supplemental curing the breast cancer. The invention has the advantages of high curative effect, small toxic and side effect and low price, etc.