2-methyl-6-acylnaphthalene (2,6-MAN) is one of the most important precursors (such as polyethylene naphthalate PEN) for polyester materials with high performances, and its highly selective synthesis is of great significance.Using 2-methylnaphthalene (2-MN) as the raw material,  acetyl chloride (AC) as acylating agent and aluminum trichloride (AlCl3) as catalyst,the effect of the reactants ratio, reaction time, reaction temperature and addition temperature on the acylation process was studied by orthogonal experiments. The acylation products were further purified by recrystallization. The effect of solvent amount and cooling rate of solution on the product purity was investigated. The results from the analyses of GC-MS, FT-IR, 1D-NMR and 2D-NMR show that the main component of acylation products is identified to be 2,6-MAN containing C6-substituted acetyl.The results of orthogonal experiments show that the ratio of reactants has the most influence on the product yield. The insufficiency of acylating agent and catalyst causes the yield decrease. The reaction temperature shows the most significant effect on the 2,6-MAN purity. When the ratio of n(2-MN)/n(AC)/n(AlCl3) is 1.00/1.20/1.45, the reaction temperature is 25 ℃, the reaction time is 4 h, and the addition temperature is -5 ℃ to -2 ℃,the resultant products yield can reach 90.93%, along with the purity of 2,6-MAN being 76.32%. When using methanol aqueous solution as solvent to purify the acylation product, the results show that high ratio of solvent/acylation product and slow cooling of the solution can improve the purity of the target product. When the mass ratio of methanol aqueous solution to acylation product is 5/1 and the slow cooling along with addition of crystal seeds is utilized, the resultant product with 2,6-MAN purity is above 98%, which can meet the oxidation need of 2,6-MAN in industry.