Abstract: Maleic anhydride (MAH) was used to corrode aramid fibers (AFs) in order to improve the interfacial compatibility between AFs and polyamide 6 (PA6) and increase the mechanical properties of AFs/PA6 composites. PA6 was mixed with AFs treated with different time gradients uniformly and the standard samples of AFs/PA6 composites were injection molded. FE-SEM, XPS, XRD and DSC were used to study the surface morphologies and element contents of AFs and the impact fracture surface morphologies, crystal form, grain and crystallinities of AFs/PA6 composites. The results show that surface roughness and surface oxygen content of AFs reach the maximum after corrosion for 3 h. The introduction of corroded AFs is beneficial for PA6 to refine grains and form α crystal. The inner of AFs/PA6 composite samples tend to form α crystal easily and the crystallinity has been improved compared with PA6. AFs/PA6 composites have higher tensile strength and bending strength after the addition of surface treated AFs, and mechanical properties of AFs/PA6 composites achieve maximum value when AFs are corroded for 3 h.