Electrochemical non-enzyme sensors based on metal and metal oxide nanocomposites are still a new challenge and a huge potential area. In this work, a ternary flower-like Cu2O-Cu-Au (CCAu) was designed and constructed as electrochemical material for glucose detection. In which, under the combined action of hydroxide ions and persulfate ions, several micrometer-long radial Cu(OH)2 branches were grown on the surface of the Cu sphere precursor. And then Au nanoparticles decorated Cu2O-Cu ternary nanocomposites formed by heat treatment and surface loading. As active materials for the electrochemical non-enzymatic glucose detection, the CCAu modified electrode showed a sensitivity of 1.082 mAmM−1cm−2 and a detection limit of 1.71 uM. The good performance of CCAu/GCE can be attributed to the compound and synergistic effect of Cu and Cu2O builds a mixed valence Cu0/Cu+, the special surface area and triple active substances with many active centers, and the dendritic structure which is conducive for the penetration of electrolyte. In addition, the CCAu electrode showed a performance comparable to that of a commercial analyzer in testing the blood glucose concentration in human serum, indicating that it has a great potential in the practical electrochemical sensors.