Organic urea compounds were prepared directly using CO2 and organic amines as raw materials without any dehydrating agent participating in the reaction process, the optimal reaction conditions were obtained by optimizing factors such as temperature, pressure, concentration, time, solvent, type and dosage of catalysts and additives. The reaction conditions were as follows: at a temperature of 190℃, carbon dioxide pressure of 4.5 MPa, inorganic base Cs2CO3 as catalyst, Bu4NBr as additive, and N-methyl pyrrolidone (NMP) as solvent, reaction concentration of 6.67mmol/mL, after 6 hours of reaction, 15 symmetric organic urea compounds with different alkyl or aryl substitutions were prepared in good yields, with yields ranging from 55% to 80%. Their structures were characterized using 1H NMR and 13C NMR, and possible reaction mechanisms were analyzed. This method has the characteristics of convenience, efficiency, environmental friendliness, and atomic economy.