Aiming at the impact of blade trailing edge perforation on aerodynamic and noise characteristics, based on NACA65019 blades, under the condition of Reynolds number Re=2×10⁵, large eddy simulation and FW-H method were used to study the influences of hole pattern and inclination angle on blade aerodynamic characteristics and flow field around blade and noise characteristics. The perforation model with better noise reduction effect was chosen to apply to the small axial flow fan. The perforation fan was tested. The results show that when the perforation angle is 30°, the aerodynamic performance of the cylindrical perforated blade is closest to the original blade within a certain angle of attack (α≤10°). In addition, the sound pressure level of the perforated blade can be reduced by 9 dB. This is because the perforated blade effectively reduces the development of vorticity along the normal direction of the blade surface, and accelerates the energy attenuation of the trailing edge vortex along the flow direction. Additionally, the jet formed by the perforation breaks the large-scale vortex to form small-scale vortices, which attenuates the wave power, reducing the aerodynamic noise.