The invention discloses essential oil handmade soap and a preparation method thereof, and belongs to the technical field of daily chemical and personal care products. The functional plant essential oil handmade soap is mainly prepared from plant polysaccharides, plant ultra-fine powder and sodium aliphatate. The preparation process of the functional plant essential oil handmade soap comprises thesteps of emulsifying essential oil by means of the plant polysaccharides, mixing the plant ultra-fine powder with the essential oil emulsion to prepare essential oil dispersion liquid, injecting the essential oil dispersion liquid into the sodium aliphatate and the like. The plant polysaccharides have excellent moisturizing efficacy, on one hand, the plant polysaccharides can emulsify the essential oil, enhance the slow release performance of the essential oil and prolong fragrance holding time to make the handmade soap exude the essential oil fragrance for a long time, on the other hand, a plant polysaccharide solution can make liposoluble and water-soluble natural moisturizing, whitening and acne-removing active components contained in the ultra-fine powder be dissolved out better, and thus the functional plant essential oil handmade soap containing the different functional components is suitable for being used by people with different requirements.