<p>Micro-fibrillated cellulose (MFC) have been prepared with dry discarded cotton cellulose by using the Fenton (Fe²⁺/H₂O₂) oxidation and high-pressure homogenization cycle method. The MFC films, with an additive amount of 2.0 wt.% MFC, were prepared by the casting method. Surface color testing, mechanical properties testing, swelling behavior, and thermal stability tests, along with ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, and thermogravimetry analyses, were used to characterize the chromaticity, mechanical properties, swelling behavior, light transmittance, chemical structure, morphological properties, and thermal stability of the MFC films. The results indicated that numerous hydrogen bonds were formed between MFC and PVA molecules. MFC was evenly dispersed in the PVA solution, exhibiting high-level interfacial compatibility. The MFC films exhibited good transparency, characterized by a ΔE value of 24.33, and they had a tensile strength of 68.25&#xa0;MPa, which was 57.04% higher than that of the PVA films. The maximum mass loss rate temperature of the MFC films was 16°C higher than the PVA films, indicating that their thermal stability of MFC films was improved by 16°C according to the maximum mass loss rate temperature. This demonstrates that the comprehensive performance of the MFC films was effectively improved.</p>