The invention discloses a myrciaria cauliflora leaf-based handmade soap and a preparation method thereof. The preparation method comprises the following steps: mixing a transparent soap base and rosehydrolat, heating in a water batch for dissolving, then adding four types of base oils, namely sweet almond oil, wheat germ oil, jojoba oil and olive oil respectively, as moisturizing agents, and thenadding a myrciaria cauliflora leaf extract concentrate and a semiaquilegia adoxoides extract concentrate, dripping in citronella essential oil and mint essential oil, uniformly stirring, moulding, standing, ventilating and drying to obtain the myrciaria cauliflora leaf-based handmade soap. The handmade soap prepared by the preparation method provided by the invention, is light brown, semitransparent, natural, safe, mild, smooth and rich in aroma, contains myrciaria cauliflora leaf fragrance, rose fragrance, citronella fragrance and mint fragrance, is a multifunctional handmade soap with antioxidant, antibacterial, itching-relieving, mosquito-repellent effects and the like.