Bismuth-based materials have excellent electrochemical properties and have been widely applied as electrode materials for energy storage and conversion. However, they are rarely used as electrocatalysts for methanol oxidation reactions (MOR). In this study, BiOBr was prepared by a simple solvothermal method and the supercapacity and MOR catalytic activity were studied. The prepared 3D flower-like BiOBr electrode showed a significant capacity of 11.46 C g−1 at 0.5 A g−1 and a retention capacity 98.72% after 10,000 cycles. When used as a MOR electrocatalyst, the BiOBr electrode maintains a current density of up to 1.28 A cm−2 in a mixture of 6 M KOH and 2 M methanol. This study will validate the feasibility of supercapacitance and MOR electrocatalysts in Bi-based materials and help develop more models and efficiency catalysts.