The invention relates to a traditional Chinese medicine composition for treating alzheimer diseases and a preparation method of the traditional Chinese medicine composition. The traditional Chinese medicine composition is mainly prepared from the following traditional Chinese medicine: ginseng, angelica sinensis, rhizoma polygonati, astragalus mongholicus, fleece-flower root, semen cuscutae, radix notoginseng, cinnamon, wolfberry fruit, rehmannia glutinosa, cornus chinensis, Chinese yam and the like. The preparation method mainly comprises the following steps that (1) placenta hominis is dried at low temperature being 60 to 65 DEG C and is pulverized into fine powder for standby; (2) the ginseng, the angelica sinensis, the astragalus mongholicus, the radix notoginseng, the cinnamon and the cornus chinensis are pulverized into fine powder for standby; (3) rhizoma acori graminei is distilled for extracting volatile oil, the volatile oil is collected for standby; and (4) residues after the volatile oil extraction of the rhizoma acori graminei are decocted with the rhizoma polygonati, the fleece-flower root and the like for 2 to 3 times, the decoction liquid obtained in three times is combined, the filtering is carried out, the filter liquid is subjected to decompression and concentration into thick paste, and the like. The traditional Chinese medicine compatibility is reasonable, good treatment effects are realized on the alzheimer diseases, the effective rate is higher than 96 percent, the preparation method is scientific and effective, the medicine restriction or the toxic and side effect generation is avoided, and the effects of each traditional Chinese medicine can be fully realized.