Abstract: In roder to simulate the errosion effects of low earth orbital atomic oxygen and study the modification effects of atomic oxygen with materials surface, an atomic oxygen beam with flix in 1013 ~1016atom/cm2× s and energy in 6~10eV has been developed by means of microwave coaxial coupling discharge of molecular oxygen plus magnetic confine and collision and reflection with a biased metal target. The produced oxygen plasma has been measured by double probe technique. The obtained oxygen beam has been calibrateed by measuring the reaction rate of kaptan with the beam. The results shows that an atomic oxygen beam with flux in 2 1016 atoms× cm- 2× s- 1 and energy in 6~20eV can be obtained by this facility.