Supported solid base K2CO3/Al2O3 prepared under microwave irradiation were found to be an efficient catalyst for the acylation of phenols with acetic anhydride in high yields under solvent-free conditions and under microwave irradiation in a short reaction time. The catalysis efficacy of supported solid bases prepared under microwave irradiation, dipping and non-supported solid bases were investigated in the acylation of phenols with acetic anhydride at room temperature. It’s found that K2CO3/Al2O3 (III-3） prepared under microwave irradiation has the best catalysis in the solid bases in the reaction. Optimized the conditions of acetylation of phenol with K2CO3/Al2O3 (III-3）, the experiment date shows that the best catalyst molar percent to phenol is 16.8mol% ,the best temperature is 60℃, the yield is 94.8% under these optimal conditions. K2CO3/Al2O3(III-3) as a efficient catalyst used in the acylation of various phenol donors was also investigated under microwave irradiation and traditional heating. The yields are 62.0%-99.8% under traditional heating in 150 min; 76.4%-100.0% under microwave irradiation in 9 min. The experimental data indicated that the general applicability and efficiency of this reaction is evident from the wide range of compounds studied. At the same time , microwave irradiation shorten reaction time largely , so it is better than the method of traditional heating.