The invention relates to a preparation method of a coal-saving combustion improver. The coal-saving combustion improver comprises 2-6 wt% of cerium nitrate, 5-15 wt% of copper nitrate, 5-10 wt% of sodium silicate, 1-5 wt% of ethanol, 0.1-1 wt% of potassium permanganate and 65-75 wt% of water. The above components are added into a liquid stirring kettle according to a certain sequence, and are uniformly mixed to obtain the product. The coal-saving combustion improver has the advantages of simple production process, reasonability in raw material selection, convenience in addition, and small dosage; and when the coal-saving combustion improver acts with pulverized coal under a high-temperature condition, the combustion-supporting time is long, the pulverized coal is combusted sufficiently torelease a large amount of heat, and the environmental pollution caused by waste gas in the pulverized coal combustion process is reduced.