The zinc-air rechargeable battery are considered as promising candidate for application in electromobility and large-scale stationary energy storage due to its high energy density , inexpensive and safety. However, the traditional battery structure limits the capacity of zinc-air battery due to ZnO generated and slow down the electrochemical reaction after discharge. A zinc-air flow battery with automatic control system is designed and manufactured, in which the flowing KOH electrolyte carries the anode electrode - zinc powder. Experiments investigated that the zinc morphology changes during the charge and discharge.The results show that several factors affect the performance and life of the battery, include the KOH concentration ,viscosity of the fluid，depth of discharge and discharge current.