A flower‐like Au microstructure with a dominantly exposed active (110) plane has been prepared by a simple, facile method at room temperature. Various experimental factors that can control the shape of the Au microflowers have been investigated and optimized. Furthermore, the glassy carbon electrode modified with these Au microflowers exhibits high electrochemical activity towards H2O2 reduction. The sensor shows a linear range from 10 μM to 5.53 mM with a detection limit of 2 μM, which can be attributed to the exposed (110) planes and 3D hierarchical structure of the Au microflowers.