The invention discloses green insecticide for vegetables and a preparation method of the green insecticide. The green insecticide for the vegetables is prepared from, by weight, the root of Chinese pulsatilla, ginger, coptis chinensis, hairyvein agrimony, radix angelicae pubescentis, pinellia ternate, garden balsam stems, mint, felwort, essential balm, potassium permanganate, pepper, pogostemon cablin, gelsmium elegans, lobelia colorata baculus, black nightshade, radix phytolaccae, hindu datura flowers, wild aconite roots, radix stemonae, common threewingnut roots, pyrethrum, lithospermum, soap nuts, shaddock peel, tobacco, Chinese azalea flowers, common carpesium fruits, areca-nuts and semen torreya. The green insecticide is prepared from the pure Chinese herbal medicine raw materials, has no toxic or side effect, does not contain any chemical matter, is free of pollution after being used, does not affect the environment and can be naturally degraded, the cleanliness of the vegetables can be guaranteed, the price is low, the materials are easy to get, pests do not easily generate insecticide resistance, promotion and use are convenient, pests of leaf vegetables can be effectively prevented and treated, the yield of the leaf vegetables is increased, and the quality of the leaf vegetables is improved.