Absorption effects of a new microemulsion absorbent on waste gas containing toluene have been studied. An oil-in-water (O/W) microemulsion was prepared by the mixture of biodiesel, water, tween-80 and n-butanol. The optimum conditions for preparation of microemulsions are as following: the mass ratio of tween-80 to n-butylalcohol is 2:1 and the HLB value is 12.33 at room temperature. The absorption results show that the removal efficiency of microemulsions for toluene can reach 91.14%. Results of the regeneration experiment indicate that the secondary recycled absorbent still have a good performance on toluene absorbing and the absorption rate is as high as 83.85%.