Abstract: The most important consideration in the design of the NAH measurement equipment is to ensure getting the accurate data of complex acoustic pressure(amplitude and phase) values in acoustic field.A scanning device of linear microphone array,which can measure the complex acoustic pressure distribution near by the noise source for NAH measurement,is recommend in this paper.The influence of acoustic scattering from the frame of microphone array on the acoustic pressure measurement is calculated,and a measure that applies damping materials to improving the accuracy of experimental measurement is put forward.The simulation results demonstrate that the sound absorbing material laying on the surfaces of the frame is effective to improving the accuracy of measurement.