Abstract: Abstract: Graphene possesses excellent chemical, physical, mechanical and thermal properties, which has attracted much attention in the past several years. Traditional Hummers-hydrazine hydrate method, mechanical stripping method, chemical vapor deposition (CVD) method, SiC substrate dependence epitaxial growth or other methods for graphene preparation use expensive graphite or gases, leading to high price of graphene. A case of point is Hummers-hydrazine hydrate method, by using the strong oxidants of KMnO4 and H2O2, graphene is prepared and has many defects (such as vacancy defect, Stone-Wales defect, doped defect and atomic absorption defect) in its structure, which would limit its application prospects. Husk, cornstalk or bagasse are common renewable biomass resources in Southern China (including Guangdong Province, Fujian Province, Hainan Province and Guangxi Zhuang Autonomous Region), which have had poor utilization ratio in the past decades. In this work, we tried to use the renewable husk resource with low price as the starting material, and by successive sulfate ions intercalation, N, N-dimethylacetamide (DMAC) thermal dispersion, microwave and ice splashing treatments, the husk-derived graphene with high added-value could be obtained. Acticarbon was prepared by high temperature carbonization, washing, vacuum drying, mesh screening and dialysis processes of husk renewable resource, which was graphitized under high-purity argon flow and high temperature (1 800℃) in the presence of Fe2O3, forming graphite crystallite with a size range of 4-25 μm. In this work, the sulfate ions with large ionic radius (0.295 nm) were used as intercalation reagent of the resulted graphite crystallite, and by successive DMAC thermal dispersion, microwave and ice splashing treatments, graphene nanosheets could be obtained readily. The characteristics of the prepared material were measured by transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectrometry (FTIR), Raman spectroscopy and X-ray diffraction spectroscopy (XRD) etc. Investigations revealed that different graphitization conditions would lead to different performance of graphene formation. We studied the performance of different graphite crystallites, including GR-110 (acticarbon without further graphitization treatments), GR-1600 (graphitization temperature: 1 600℃) and GR-1800 (graphitization temperature: 1 800℃). Among all candidates, graphite crystallite GR-1800, catalyzed by Fe2O3 at 1 800℃ under argon atmosphere, could lead to the optimal morphology of graphene. From TEM and SEM results, we could observe that the prepared graphene nanosheet had a size range of 4-25 μm, and the characteristic wrinkle structure of graphene could be observed readily in the TEM images. As illustrated in AFM image, the prepared graphene nanosheets had a thickness of 0.8-1.75 nm, which could be contributed to 1 or 2 layers of graphene nanosheets. The size of such graphene nanosheets detected by AFM was about 6 μm. In the FTIR results, the prepared nanocomposites had a typical skeleton vibration peak at 1 550 cm-1 for graphene, and more importantly, no obvious peaks at 3000-3600 cm-1 and 1250 cm-1 could be observed in the prepared material, which could be found in graphene nanomaterials prepared by traditional Hummers-hydrogen hydrate method, owing to vibration peaks for residual -OH or other groups in graphene oxide (we also called it defects of graphene). XRD pattern in this work revealed that the nanomaterials had a peak of 24.7°, which was the characteristic peak of graphene. In Raman spectroscopy, the height of two-dimensional band, which was the important factor for graphene layer amount, was double times that of the G band of the resulted graphene, and based on previous reports, we usually considered that such graphene nanomaterials were 1 or 2 layers of graphene nanosheets. Meanwhile, the D band of the prepared graphene, which concerned with the different defects of the graphene, was much lower than the traditional Hummers-hydrazine hydrate method graphene, which indicted that graphene nanosheets prepared by this work had lower defects. Meanwhile, after careful calculation, the price for the 1 or 2 layers of husk-derived graphene nanosheets prepared in this work was about RMB 375/g (about 61.3 USD/g), much lower than the current price of similar products in Chinese graphene market (over 163.5 USD/g). This work can provide a new approach to large-scale and high-quality synthesis of cheap graphene nanosheets by husk or other renewable biomass resources.