Abstract: The aerodynamic performance of the two-stage supersonic ejector is investigated by the Ma5~6 experiment on the FD-07 wind tunnel of CAAA. The experimental data is acquired by the test of the second stage ejector, the combined test of the first and the second stage ejectors, and the combined test of the main flow and the secondary flow. The conclusion can be organized as followed:(1) The ejector operating efficiency is higher and medium pressure gas consumption is less when the work pressure ratio of the two-stage ejector is setted to 0.8MPa and 1.0MPa, respecticely. (2) The low pressure environment of the test section is mainly determined by the main air flow. As far as the start-up pressure ratio of the wind tunnel is satisfied, the ope-rating parameters of the ejector have little effect on the pressure of the test section. (3) The first-stage supersonic ejector can be well segregated from the main airflow disturbance and the second-stage supersonic airlow interference, which is instructive for the theoretical study of the multi-stage ejector. The research work is carried out with the actual wind tunnel as the object, and effectively solves the problem that the running state of the FD-07 wind tunnel ejector is not clear. The ejector operating pressure scheme has been optimized so to be energy saving, and it has practical significance for the hypersonic wind tunnel performance improvement. The relevant test data can provide a reference for the study of aerodynamic performance of the supersonic ejector.