An ejector test facility was established to investigate the multi-nozzle supersonic ejector performance, and hot rocket exhaust gases were used as primary and secondary driving fluids. Emphases were placed on pressure matching between primary and secondary flows. The investigation indicates that the higher the total pressure of primary flow is and the lower the static pressure of on primary nozzle exit is, the more convenient it is for the performance to match with the secondary flow, and that the lower the secondary flow total pressure is, the more the critical ejector performance is required to maintain pressure matching, and that the secondary flow total temperature has little influence on pressure matching.