Abstract: Methyl tert-butyl ether (MTBE) is an important high octane additive for the production of clean gasoline. It is necessary to reduce sulfur in MTBE to less than 10μg/g to meet increasingly stringent standard for motor gasoline. According to the weak acidity property of mercaptan, this work uses an alkali washing-extractive distillation combination process for MTBE desulfurization. The S content is reduced from 132.5 μg/g to 76.2 μg/g in alkali washing stage at conditions of NaOH of 28%, NaOH/MTBE mass ratio of 0.015, alkali washing temperature of 35℃, alkali washing time of 6s, separated temperature of 35℃, separation time of 5min. The MTBE after alkali washing then undergoes three-stage extraction distillation by DMF at 80℃, distillation time of 25min, solvent/oil mass ratio of 1.5. The results show that the sulfur content of MTBE can be further reduced to 8.7μg/g and the total liquid yield of the combined process is 99.64%. The solvent after six times regeneration recycle can still reduce the sulfur in feed to less than 10μg/g. The regeneration conditions are: N2 stripping with space velocity of 60h-1 at 100℃.