Abstract: To investigate the influence of the cross-section shape of polyester fiber on the sound absorption performance, four kinds of polyester fiber panels with different cross-section shapes are prepared by hot pressing method. The impedance tube is used to measure the sound absorption coefficient in the frequency range of 80~6 300 Hz. The sound absorption property of the material is predicted according to the flow-resistance model and the acoustic impedance model. The model calculation results are compared with measurement results. The results show that the polyester fiber material with flat cross-section has the best sound absorption property and the average sound absorption coefficient reaches 0.404; the measured sound absorption coefficient of the polyester fiber material with circular cross-section is in good agreement with the model calculation result, the error rate is 2.036% in the whole frequency range, but for the polyester fiber material with other cross-section shapes, the error is large.