The need suppress aerodynamic noise in open cavities represents an important problem in aeronautical applications. Acoustic field of the standard cavity model is simulated by using the non-linear disturbance equations and synthetic reconstruction of turbulence based on the RANS equation. The reliability of the method is validated by comparing the result with the experimental data. Based on this, the impact of passive control measures of baffles on cavity turbulent kinetic energy, velocity profile, sound source distribution, pulsating pressure distribution and spectrum characters are also analyzed. The analysis indicates that, the strength of the sound source cannot be reduced only by altering the direction or intensity of the shear layer, the maintaining of the stability of the shear layer is also required to influence the distribution and strength of turbulent kinetic energy and sound source, so as to reduce the flow oscillation effects. The results show that the passive control measures can effectively decrease the cavity aerodynamic noise , which have a certain value in engineering applications.