The invention discloses alcohol base gasoline solubilizer and a preparation method thereof. The solubilizer comprises isopropyl ether, acetamide, alkylphenol polyether, methyl tert-butyl ether, fatty acid methyl ester, furan, tertiary butanol, antioxidant and anti-swelling agent. The preparation method comprises the following steps: weighing isopropyl ether, tertiary butanol, acetamide, alkylphenol polyether, methyl tert-butyl ether, fatty acid methyl ester, furan, antioxidant and anti-swelling agent according to a certain weight ratio, adding isopropyl ether and tertiary butanol in a reaction kettle for vacuumization, warming the reaction kettle, adding acetamide, stirring, adding alkylphenol polyether, stirring and cooling through a cooler, adding methyl tert-butyl ether, fatty acid methyl ester, furan, antioxidant and anti-swelling agent, and uniformly stirring to obtain the alcohol base gasoline solubilizer. The invention has no toxicity, no pollution and no special odor, less adding amount, good solubilizing effect, and no heavy metal component, no generation of new pollution and no mechanical impurity, and can increase the octane of 90# gasoline to 95-99#.