In order to analyze the static electric field distribution of non-steady-state process under concentration polarization conditions,the Laplace transform was used to solve the change of oxygen concentration on the surface of the electrode based on the Fick second law. The current density of galvanic corrosion controlled by oxygen concentration was analyzed through Faraday law, in the basis of which the instant potential and static electric field in any position of electrolyte can be obtained through current element, and then to verify the correctness by experimental results. The results show that the static electric field and potential decrease with time and reach a steady state finally, while the current density decreases with the decrease of oxygen concentration.