The requirements for wastewater treatment is getting higher and higher,as the national economy in China is developing rapidly.It would be a good method to use pure oxygen aeration technique in sewage treatment.By the analysis of the expansion project of Jimo sewage treatment plant,the paper discussed the theories of pure oxygen aeration technique,the selection of the technology and the economic analysis of pure oxygen aeration technique,discussed the feasibility of the use of pure oxygen aeration technique in sewage treatment.As the new national standards improved the requirement of nitrogen and phosphorus removal,pure oxygen aeration shows great prospects in the construction of sewage treatment plant.