The invention relates to a preparation method of a quinoline compound. The structural formula of the prepared quinoline compound is shown as the figure attached in the specification, wherein R1, R2, R3, R4 and R7 are hydrogen atom, alkyl, aryl, halogen, alkoxy, aryloxy, trifluoromethyl and the like, R5 and R6 are hydrogen atom, alkyl and aryl. The preparation method includes: taking 2-nitrobenzyl alcohol and acetophenone as raw materials, under alkaline catalysis, carrying out complete stirring reaction at 55-65DEG C for 24h, at the end of the reaction, extraction, performing extraction, organic solvent washing, concentration, and column chromatography purification to obtain a quinoline compound with a yield of 60-85%. Specifically, the alkaline is potassium tert-butoxide, potassium hydroxide and sodium hydroxide, etc. The method provided by the invention has the characteristics of stable and easily available raw materials, mild reaction conditions, good product selectivity, simple operation, and suitability for industrial production, etc.