The invention discloses a traditional Chinese medicine for treating cardiovascular and cerebrovascular diseases and a preparation method thereof. The traditional Chinese medicine is composed of the following raw materials in proportion by weight: 64-84 parts of astragalus, 64-84 parts of salvia miltiorrhiza, 27-47 parts of codonopsis, and 27-84 parts of Radix Ophiopogon japonicus. 47 parts, 49-69 parts of Alisma, 27-47 parts of roasted licorice, 27-47 parts of schisandra, 27-47 parts of rehmannia, 27-47 parts of angelica, 27-47 parts of safflower, 27-47 parts of cassia twig, red 27-47 parts of peony, 19-39 parts of Chuanxiong, 49-69 parts of hawthorn, 27-47 parts of Poria cocos, 19-39 parts of coptis, 27-47 parts of Citrus aurantium, 49-69 parts of keel, 49-69 parts of oyster, cassia seed 49 to 69 parts, 49 to 69 parts of Jiaogulan, and 27 to 47 parts of Plantago Seed. The traditional Chinese medicine can not only reduce blood viscosity in a short period of time, change the state of myocardial tissue ischemia and hypoxia, and gradually restore heart function; hospitalization is avoided, and more than 80% of patients are free of stent or bypass.