Abstract: Poly-alpha-olefins synthetic oil (PAO) was one of the most widely used synthetic lubricants at present. The oligomerization of C6, C10, C12 α-olefins was studied with CF3SO3H as catalyst. The effects of process conditions including catalyst dosage, feed composition, reaction temperature and reaction time, on the PAO yield and the performance of synthetic lubricant were studied. Results showed that under the conditions of catalyst/feed molar ratio of 0.36, reaction temperature of 40 ℃ and reaction time of 3 h, PAO with low viscosity (100 ℃ kinematic viscosity of 4.83 mm2/s), low condensation point (-30℃) and high viscosity index (140) was synthesized with a yield of above 70 %, and its performance well met the requirements of base oil for high quality PAO synthetic lubricants.