The invention provides a special organic-inorganic mixed fertilizer for grapes, and a preparation method of the special organic-inorganic mixed fertilizer for grapes, belonging to the field of special fertilizer for plants. The mixed fertilizer comprises the following substances in parts by weight: 350-400 parts of organic fertilizer, 50-70 parts of soil fertility intensifier, 80-120 parts of monoammonium phosphate, 160-200 parts of urea, 6-10 parts of ammonium nitrate, 10-30 parts of potassium sulfate, 3-4 parts of carboxymethylcellulose, 0.3-0.5 part of boric acid, 0.5-0.7 part of cartap, and 1-3 parts of chlorothalonil. The special organic-inorganic mixed fertilizer for grapes is formed by compounding different raw materials according to absorption rules of grapes; and with the adoption of the special organic-inorganic mixed fertilizer for grapes, output can be increased and the quality of grapes is improved, damage to roots of grapes due to multiple fertilizer application is avoided, and the fertilizer efficiency is prolonged.