The invention discloses a [Miaoxinkang] detoxifying and beautifying bath decoction, which consists of the following raw materials in parts by weight: 8-16 parts of herba lysimachiae, 4-10 parts of radix scutellariae, 6-12 parts of radix glycyrrhizae preparata, 5-7 parts of radix astragali, 9-15 parts of radix codonopsitis, 9-15 parts of flos rosae rugosae, 9-15 parts of santati album, 6-12 parts of radix angelicae dahuricae, 9-15 parts of seed of Chinese dodder, 6-12 parts of semen platycladi, 4-10 parts of radix paeoniae alba and 9-15 parts of lilium brownii. According to the [Miaoxinkang] detoxifying and beautifying bath decoction and a preparation method thereof, Chinese herbal medicines are Chinese-specific products on the basis of the theory and practice of traditional Chinese medicine, and a proper medicated bath formula is adopted; drug effects can act on skin surface, local parts and affected parts of whole body; the bath decoction, which is absorbed, can promote circulation ofmeridians and blood and internally reach internal organs from outside to inside so as to take effects; the medicated bath, when adopted in a bath, can take such health-care effects of dredging meridians, promoting blood circulation and removing stasis, expelling wind and dissipating cold, clearing away heat and toxic materials, relieving swelling and alleviating pain, regulating yin and yang, coordinating the internal organs, promoting circulation of qi and blood, nourishing whole body and the like; the medicated bath, when applied, can improve contents of some immune globulin in blood and enhance skin elasticity and activity; and through frequent application, the medicated bath can keep people more healthy.