Dielectric barrier discharge (DBD) can produce non-thermal plasma under atmospheric pressure, which has broad prospect in sewage treatment technology. In this paper, the dielectric barrier discharge structure is designed and the coaxial discharge structure is used. The experiments show that the structure is safe and reliable. At the same time, it has low discharge power and can discharge uniformly. So, the plasma produced by dielectric barrier discharge can be convenient and easy to used in sewage treatment, and the result is effective.