Abstract: The aerodynamic characteristics of an aeroengine test chamber affect the accuracy of engine performance evaluation. To improve the flow field uniformity in a specific aeroengine test chamber, four smoothing system shcemes for the diffuser and pressure stabilization sections of the front compartment were investigated. These systems included elements such as deflector plates, conical perforated plates, flat perforated plates, honeycombs, and mesh screens, among others. Computational fluid dynamics (CFD) methods were employed to calcute the flow fields within the front compartment, incoming air pipe, and associated air valve for each proposed system. The results revealed that the valve within the incoming air pipe had some impact on the incoming flow field, resulting in uneven airflow entering the front compartment. While deflector plates and conical perforated plates reduced the mixing of the incoming flow, their effectiveness in improving the flow uniformity in test chambers with non-uniform incoming airflow was limited. Incontrast, multi-layer flat perforated plates demonstrated superior performance in flow conditioning within test chambers with non-uniform incoming airflow. These findings provide references for the design of intake smoothing systems for aeroengine test chambers.