Abstract: The principle of the facility operation is introduced.The facility for simulating atomic oxygen in low Earth orbit adopts coaxial microwave plasma source.The components of the facility and their functions are described.The measuring methods and measured results for performances are described.It is proved that energy of atomic oxygen can be controlled in the range of 5eV～10eV,beam intensity of atomic oxygen is about 4×10 15 Atom/cm 2·s and the content of oxygen ions is less than 0 1% in atomic oxygen beam.