The work aims to introduce the research approach and developed supporting testing equipment of external coating damage inspection for submarine pipelines in paralic zone based on DC potential gradient method. Feasibility of DC potential gradient method in external coating damage inspection for submarine pipelines in addition to applicability of detector operating and measuring functions were investigated by virtue of a simulative test. This method was proved to be effective by the simulative test. Damage larger than 8 mm×8 mm (8 mV/m) on the external coating could be inspected contactlessly in regardless of the effects of normal filling of submarine pipelines. The external coating damage inspection technology for submarine pipelines in paralic zone based on DC potential gradient method turns out to be feasible. Position of external coating damage and sacrificial anode can be determined by utilizing the developed detector and measuring potential gradient along the submarine pipelines. This method can provide technical support for operation and maintenance of the submarine pipelines.