4-Allyloxymethyl-1,3-dioxolan-2-one (AGC) was prepared by the coupling reaction of allyl glycidyl ether (AGE) and CO2 using 3-bromo-1,1,1-trifluoro-2-propanol (BTFP) as activator. The coupling reaction was catalyzed by TBAB organocatalyst. Many kinds of quaternary ammonium salts and activators were screened. The effects of reaction temperature, activator amount, carbon dioxide pressure and reaction time on the yield of the product were investigated. A possible reaction mechanism was proposed. The product was analyzed by gas chromatography coupled with mass spectrometry (GC-MS), infrared spectroscopy (FTIR) and - nuclear magnetic resonance spectroscopy (1H-NMR, 13C-NMR). The results demonstrated that the yield of the corresponding cyclic carbonate could reach 96.5% when BTFP was 2 mol% of AGE, n-butylammonium bromide (TBAB) was 2 mol% of AGE at 0. 5 MPa CO2, 90 ℃ for 18 h under a solvent-free condition.