The invention discloses a traditional Chinese medicine composition for treating chronic cardiac failure and a preparation method thereof, applied to the field of traditional Chinese medicines. The traditional Chinese medicine composition comprises traditional Chinese medicine main ingredients and medicinal auxiliary materials, wherein the traditional Chinese medicine main ingredients comprise astragalus, cassia twig, salvia miltiorrhiza, Chinese angelica, ginseng, red flower, motherwort, semen lepidii, poria cocos and pseudo-ginseng; and the medicinal auxiliary materials comprise dextrin, starch and lactose. The preparation method comprises the following steps: heating, refluxing and extracting astragalus, ginseng, pseudo-ginseng, poria cocos, salvia miltiorrhiza and semen lepidii according to a prescription ratio by using ethanol twice, filtering, merging the filtrate, and recovering ethanol to obtain liquid medicine; soaking cassia twig, red flower, motherwort and Chinese angelica according to the prescription ratio, adding the obtained medicine residue, decocting by using water, filtering to obtain liquid medicine, decocting by using water, filtering to obtain liquid medicine, and collecting distillate twice to obtain the liquid medicine; performing spray drying on the concentrated solution, and preparing extract powder; and adding the extract powder into dextrin, uniformly mixing, wetting the granules by using ethanol to obtain a finished preparation. By adopting the method for tonifying qi, promoting blood circulation to remove blood stasis and warming yang to promote diuresis, the clinical symptoms of heart failure patients are improved, the myocardial contractility can be improved, and the pumped blood of venous return is increased, so that the heartbeat is increased, and the myocardial infarction range is narrowed.