The invention discloses a natural bacteriostatic hand washing solution and a preparation method thereof. Raw materials of the hand washing solution comprise the following components: 30 to 40 parts of a surfactant, 10 to 15 parts of a thickening agent, 8 to 10 parts of an antiseptic, 10 to 12 parts of active carbon, 10 to 15 parts of rosemary essential oil and the balance being water. The preparation method of the natural bacteriostatic hand washing solution is simple, and the preparation process is convenient. The natural bacteriostatic hand washing solution provided by the invention is prepared from pure natural raw materials, is safe, nontoxic and green, and meanwhile has functions of sanitation, health and skin care. Soya lecithin has functions of emulsifying, dispersing, foaming and moistening; pectin has a thickening effect; active carbon can absorb stains, sterilize, remove smells, prevent mildew and detoxicate; the rosemary essential oil has delicate fragrance and can restore consciousness, promote blood circulation and condition skin; and cassia seed extract has antiseptic and bacteriostatic functions.