The invention discloses a nonmetallic gasoline additive and a method for preparing the same. The nonmetallic gasoline additive comprises, by weight, 0.5-12% of polyether, 0.5-12% of polyether polyol,0.5-10% of poly-alcohol, 0.1-15% of catalysts, 0.1-15% of stabilizers, 1-16% of soluble silicic acid and 55.9-92% of polyol. The method includes adding the polyether, the polyether polyol, the poly-alcohol and the catalysts into the polyol; carrying out stirring reaction to obtain transparent oily liquid; adding the soluble silicic acid into the liquid; carrying out stirring reaction at the temperature of 80-110 DEG C until solution turns clear; filtering the clear solution to obtain the nonmetallic gasoline additive. The nonmetallic gasoline additive and the method have the advantages that more than 18% of gasoline can be saved by the aid of the nonmetallic gasoline additive under identical conditions, emission of hydrocarbon HC, carbon monoxide CO, PM (particulate matters) and nitrogen oxide NOx can be reduced to a great extent, the smoke intensity can be lowered to a great extent, and effects of inhibiting carbon deposit generation and eliminating carbon deposits can be realized; the nonmetallic gasoline additive is stable in property, can be safely stored and transported and is free of damage to gasoline cylinders and engines, the nonmetallic gasoline additive and gasoline arecompletely mutually soluble, precipitation and layering can be prevented.