Multifunctional textiles based on cotton have attracted wide attentions recently. In this study, the cotton fabrics were synergistically modified by surface micro-dissolution and cationization to enrich the adsorption of negatively charged graphene oxide (GO) on it. Subsequently, the bound GO was chemically reduced to rGO by using L-Ascorbic acid to endow cotton with high UV resistance and conductivity. By XRD, FTIR and zeta potential analysis, it was concluded that the synergistic modification could alter the structure of cotton and at the same time facilitate the reactions between cotton molecules and cationic agent EPTAC. This would shield more negative charges in cotton to decrease its absolute zeta potential, enhancing the uptake of negatively charged GO on the surface of cotton significantly. In addition, SEM, FTIR and Raman spectroscopy were utilized to confirm the presence of rGO on the surface of cotton fabrics. The result from resistance measurement disclosed that the synergistic modification could significantly reduce the electrical surface resistance of cotton to 3.89 × 103 Ω/sq. Moreover, the synergistic modification could greatly improve the UV protection factor (UPF) of cotton from 24.18 to 487.91, far beyond the excellent UPF rating (50+). The high UV resistance and conductivity of this rGO coated cotton fabrics suggests that they can be used as functional textiles for various applications.