Abstract: Controllable preparation of defect graphene was successfully realized by reducing cheap sugars with active metal sodium. The graphene material showed excellent humidity sensitivity at room temperature. The characte-rization results showed that the addition of sugars increased the thickness of graphene to 0.4 nm and changed the surface modification groups of the defective graphene and their content(mole ratio). The mole ratio of oxygen-containing groups on the surface of defect graphene prepared with the sucrose precursor is up to 24.2%. The humidity sensitivity of graphene samples with different defect contents at room temperature varies. Compared with the samples without sugar, the room-temperature humidity sensitivity of the defective graphene prepared with the sucrose precursor can be improved by 4.5 times. This study can provide technical reference for the application of graphene-based materials to room-temperature gas sensing.