The invention discloses an electrode material treating method for an electrochemical flow cell. In the method, low temperature and normal pressure plasma technology is adopted for conducting surface treatment on electrode materials, gas flow is adopted to adjust the intensity of the plasma, and the surface treatment effect is adjusted through adjusting the relative motion speeds and the distance between the electrode materials and the nozzle of a low temperature plasma electric discharging device. The method provided by the invention has the benefits that etching in electrode materials treatment is conducted under room temperature, and damage on the electrode materials caused by high temperature is avoided; the surface treatment effect can be effectively controlled solely by adjusting the distance between the gas flow and the nozzle through the adoption of the plasma technology; continuous treatment on materials is realized without arranging a vacuum environment or an airtight cavity; no inorganic or organic solvent is required during a treating process, and as only electric energy and oxygen are consumed, the method is low in energy consumption, safe and environmental-friendly; the material surface is treated uniformly, the treatment time is short, the electrode material treating method is extremely easy to be used for mass production, and is simple in technology and low in cost.