Large-scale production of high-quality graphene nanosheets has been considered to be an interesting and significant challenge. A new approach is reported regarding the fabrication of high-quality graphene nanosheets via chemical reduction with the combination of reducing reagents from graphene oxide (GO). High-conducting reduced GO (RGO) was provided with the combination of hydrazine hydrate and hydroiodic acid. RGO was characterised by X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, Raman, thermo gravimetric analysis, atomic force microscopy and four-probe conductivity tester. Characterisation results indicated that oxygenated functional groups were removed from GO, and high graphitisation has occurred in GO reduction process. The electrical conductivity of RGO was considerably improved and the C/O ratio of RGO was higher than that prepared by single reducing reagent. Combination of hydrate hydrazine and hydroiodic acid have showed high reduction efficiency and good synergistic effect in GO reduction process. The findings in this work can promote research on prepared graphene-based nanosheets composites by a quick and effective processing technique.