Abstract: Aerodynamic performances of the axial compressor of the 0.6 m continuous transonic wind tunnel are tested under various pressure conditions, and the Reynolds number effects are studied experimentally. The lowest total pressure of the compressor inlet is about 3 kPa, and the corresponding Reynolds number is approximately 5×10⁴. Test results show that the Reynolds number effects are significant when as Reynolds number is below the critical value, which is 5×10⁵ in the compressor design. Compared to the large Reynolds number condition, the pressure ratio under the low Reynolds number condition reduces rapidly, while the surge margin changes slightly. The mechanical loss of the shaft becomes the major loss of the compressor as the operation pressure drops, and has a significant influence on the compressor efficiency. Additionally, the correlations of the pressure ratio and efficiency with Reynolds number, obtained by data analysis, can offer a useful reference for design and numerical simulation of the axial compressor under the at low Reynolds number condition.