A non-enzymatic sensor nanomaterial which is composed of ultra-thin scaly CoMn2O4 nanosheets grown on the surface of reduced graphene oxide sheets (CoMn2O4 NSs/rGO) has been successfully synthesized by a simple method for glucose sensing. The morphology and elemental composition of CoMn2O4 NSs/rGO are researched by means of x-ray diffraction, field emission scanning electron microscope, and transmission electron microscope. Cyclic voltammetry and amperometry are used to analyse the glucose oxidation characteristics of the material. The test results show that the non-enzymatic glucose sensor based on CoMn2O4 NSs/rGO has excellent glucose sensing performance, exhibiting a wide linear range of 0.1–30 mM with high sensitivity of 6830.5 μA mM−1 cm−2, which is better than other glucose sensors. In addition, the CoMn2O4 NSs/rGO sensor has superior anti-interference and stability. More importantly, the sensor can be applied to the measurement of real sample, which makes it have the potential to become a reliable clinical glucose sensor.