The invention provides natural herb skin-care soap and a preparation method thereof. The preparation method comprises the steps that anemone, ageratum conyzoides and yarrow are taken, soaked with cold water and decocted twice by adding water, and then concentration is conducted to obtain water decoction; 2, erica flowers and michelia flowers are taken, dewatered, pulverized and screened with a sieve, and erica flower powder and michelia flowr powder are obtained; 3, coconut oil, palm oil, olive oil, dracontomelon duperreanum fruit oil and ardisia crenata fruit oil are added into a container, fully stirred, heated and then cooled by standing; 4, sodium hydroxide is slowly added into water, stirring is conducted while sodium hydroxide is added, and sodium hydroxide is completely dissolved in water; 5, the materials obtained in the step 1, the step 2 and the step 4 are all poured into the container containing the mixed oil, quick stirring is conducted while the materials are poured, a reaction is conducted, soap liquid is obtained, stirring continues until the soap liquid is thick, then the mixed soap liquid is poured into a mold, and the finished soap product is obtained. The soap has a certain bacteriostatic effect and can improve acnes and enable the skin to be moisturized, glossy and elastic.