The invention discloses diaper rash cream for a baby and a preparation method thereof. An aloe extract, tea polyphenol, honey, carrot juice and a sunflower extract are added into a 0.9% sodium chloride solution to prepare a water-phase matrix, then the viscosity of the matrix is regulated by corn starch, oil-phase components including sesame oil, glycerol and sunflower seed oil are added finally, and the water-in-oil type product is prepared. According to the diaper rash cream, a pure plant formula is adopted, no irritation component is contained, a protective film can be formed on the surface of the baby skin, the hip skin of the baby is moistened, the phenomenon that urine directly irritates the skin is avoided, generation of eczema and inflammations caused by urine irritation are effectively prevented, redness caused by the eczema can be effectively relieved, the skin around the anus can be protected, growth of fresh tissue can be promoted, skin redness is effectively relieved, the satisfied treatment effect is achieved, and pain of the patient baby is relieved.