Abstract: The ejector nacelle has the capability to simulate the effect of jet flow and partly to simulate the effect of inlet flow, so it can be used to study the aerodynamic interference characteristic of engine on wing and high lift systems. Because of the advantages of short testing period and low cost, the ejector nacelle becomes a key testing technique for aircraft-engine integration research in wind tunnel.This paper presents the recent development in ejector nacelle simulation testing in low speed wind tunnel in China Aerodynamics Research and Development Center (CARDC). The flow field and characteristics of the ejector nacelle are simulated by computational fluid dynamics software. Based on numerical simulation results, the diameter of sonic nozzles and the position of sonic nozzles are optimized, the inlet mass flow is increased, the uniformity of outlet flow field and the performance of the nacelle are improved. The air bridge technique is developed and optimized by finite element analysis. The rigidity of the air bridge and the balance are matched basing on air bridge and balance assembly numerical simulation. The rigidity effect, the pressure effect, the temperature effect and the mass flow effect of the air bridge are corrected by serial tests. This correction further minimizes residual force of the air bridge. The high accuracy flow measurement and control techniques including the digital valves, the mass control units and the measurement rake are adopted in the ejector nacelle simulation testing. These techniques improve the precision of the control and the uncertainly of the flow measurement. The precision of the mass flow control is within 0.1%, the uncertainty of the mass flow measurement is 0.3% and the precision of pressure ration 0.01. The moving support system is developed for engine position optimization research. The performance test and wind tunnel test using the ejector nacelle are introduced. The test results show that the effect of the engine increases the slope of lift curve, increases the stall angle of attack, decreases the zero angle lift coefficient.