The invention relates to a preparation method of moisturizing antibacterial bath lotion. The technical scheme is as follows: respectively weighing persicaria perfoliata extract, eclipta extracts, lygodium extract, tea saponin, tea seed oil, wormwood extract, herba violae extract, liquid soap base, sodium hyaluronate and deionized water; first, mixing the persicaria perfoliata extract, eclipta extracts, lygodium extract, wormwood extract and herba violae extract, heating and maintaining at 50 DEG C, adding the tea saponin and the sodium hyaluronate, continuing stirring for 20 to 30 minutes to prepare the moisturizing antibacterial bath lotion. The advantages of the bath lotion are that: the bath lotion is preparepd by natural plants, can deeply clean the skin, has the effects of whitening, moisturizing, and brightening skin, is non-irritating to the skin, can inhibit a variety of kinds of bacterium and dermatophyte, has anti-inflammation and anti-swelling effects on skin inflammation, and has the features of easily available raw materials, mild reaction condition, easy operation, obvious effect, low cost, and the like.