The invention relates to silicon-titanium fertilizer and a preparation method thereof. The silicon-titanium fertilizer is prepared from raw materials in parts by weight as follows: 10-12 parts of silicon dioxide, 0.3-0.5 parts of titanium dioxide, 15-20 parts of humic acid, 6-10 parts of corncobs, 7-12 parts of soybean meal, 5-8 parts of corn flour, 10-15 parts of pig manure, 2-5 parts of tourmaline, 0.01-0.1 parts of sodium chloride, 0.2-0.3 parts of sodium pyrophosphate, 0.05-0.1 parts of ammonium molybdate, 0.2-0.4 parts of carboxymethyl cellulose sodium, 10-12 parts of a leavening agent and 900-1000 parts of water. The silicon-titanium fertilizer contains multiple elements such as silicon, titanium, boron, iron, manganese, zinc, copper and the like and can be in a needle shape on leafsurfaces when sprayed to the leaf surfaces so as to repel pests such as red spider mite and the like, hazardous substances are adsorbed and decomposed, plant resistance is improved, nutrient uptake ofthe plants is promoted, crop quality is improved, penetration rate for cell membranes is increased, and plant metabolism is promoted.