The two-dimensional axial model is adopted to study the flow characteristic in supersonic nozzle using ideal gas as medium. Experimental platform is set up to study the influence of structural and operating parameters on flow field and separation efficiency under low pressure ratio. The numerical results indicate that there is no shock wave in the nozzle divergent section when pressure ratio is 1.4

outer angles of liquid discharge chamber is less than 12° and area ratio is 1.27. Meanwhile

the analysis of the leading shock waves indicates that the reverse compression waves appear in the liquid discharge chamber and move to nozzle upstream. The experimental results show that the highest separation efficiency of the supersonic gas separator (SGS) can reach 20.5% when the pressure ratio and area ratio are set to 1.4 and 1.27

respectively.