ABSTRACT: High magnetic loss and saturated magnetic conductivity endow FeSiAl sheets with broadband microwave absorption properties. However, due to thick sheet thickness and rigid sheet, the mechanical properties and flexibility of FeSiAl films are poor, greatly influencing its use in flexible electronic devices. In this study, a small amount of water is introduced into the aramid nanofiber (ANF) suspension to recover their intermolecular hydrogen bonds. By controlling the water content, the FeSiAl/ANF nanocomposite films exhibit excellent mechanical properties and flexibility. The result indicates the nanocomposite films show high flexibility and good microwave absorption properties when the ANF content reaches 60 wt%. The stress and strain of the nanocomposite films can reach 136.88 MPa and 4.72 %, respectively. When the thickness reaches 3 mm, the effective absorption bandwidth and the reflection loss are 2.84 GHz and -46.81 dB. Besides, the nanocomposite films can resist folding circles. The easy and green preparation process endows the nanocomposite films with great potential application in the microwave absorption field of flexible electric devices.