"Cross Flow Fan" of the noise and the control measures in recent decades, due to the rapid development of industry, industrial noise and more serious, has become one of the hazards of environmental pollution. Power plant equipment, piping systems and valves is mainly composed of noise. Various types of pump and fan noise they produce is also quite serious, in which the axial fan is the worst. The noise on people's health is very harmful. Therefore, controlling the noise source, noise reduction is very important, but is also increasingly being recognized.