In the past few years, there has been a notable rise in the release of industrial waste oil, frequent oil spills at sea, and a significant escalation in the severity of water pollution. This issue has garnered global attention and is now recognised as a widespread concern. Hence, there is a pressing demand for an oil-absorbing material exhibiting high oil-absorption capabilities and robust mechanical properties. This study introduces a new aerogel characterised by a three-dimensional hierarchical pore size structure derived from natural corn stalk powder and graphene oxide (GO). The developed aerogel demonstrated notable sorption capacity ranging from 70.6 to 131.0 g/g, along with excellent compressibility and high elasticity. These properties enable effective oil-water separation and selective sorption. This study introduces a novel approach to treating agricultural waste and presents a straightforward, environmentally friendly, cost-effective method for synthesising high-performance graphene-based oil-absorbing agents.