The utility model relates to a sour reaction unit falls in heterogeneous esterifying belongs to the chemical industry equipment field. The esterification reaction system adopts the heating of oil bath pot, and the left end mouth and the automatic sampler of esterification reaction ware are connected, goes up the port and is equipped with the three -dimensional linker, and the right -hand member mouth is equipped with temperature sensor I, methyl alcohol steam generation system adopts the water -bath heating, methyl alcohol steam generator's left end mouth is equipped with the methyl alcohol rectifying column, methyl alcohol steam generator's last port and three -dimensional buffering linker are connected, methyl alcohol steam generator's right -hand member mouth is equipped with temperature sensor II, flow regulator is passed through to methyl alcohol rectifying column upper end gas outlet, steam mass flow meter is connected with the air inlet of three -dimensional linker, methyl alcohol rectifying column right -hand member is equipped with mercury glass rod thermometer, three -dimensional buffering linker upper end and condensing reflux union coupling, three -dimensional buffering linker left end lateral duct is crossed the pipeline and is connected with the gas outlet of three -dimensional linker. The utility model discloses can show improvement reaction efficiency, the shortening reaction time.