<p>Given the distinct characteristics of soil structure and the thermal effects arising from the electro-thermal properties of seawater, investigating the temperature growth behavior of marine DC grounding electrodes and perfecting design solutions are of great significance to guaranteeing the consistent operation of offshore wind energy direct current systems. Innovatively, we construct a finite element model of marine DC grounding electrode considering circuit and electro-thermal field interaction; the model premeditates the impact of temperature features of seawater electro-thermal characteristics on the temperature growth behavior of the electrode, uses a novel circuit model to simulate the uneven current distribution phenomenon in each conductor segment, and combines the electro-heat field interaction model to calculate the electro-heat field distribution characteristics of the marine electrode during the dissipation process. Furthermore, we discuss the impact of elements including the quantity, length, pole spacing, distance from the shore, underwater depth, and coast angle on the temperature rise performance. The results suggest that: (1) Increasing the number, length, pole spacing, and distance from the shore can reduce the highest temperature rise and improve the end effect, but the pole spacing and distance from the shore have little effect; (2) As the depth increases underwater, the temperature growth distribution becomes more and more uneven. In engineering applications, the top of the electrode should be set close to the sea surface to dissipate heat; (3) The smaller the coast angle, the lower the temperature rise. When selecting a site, priority should be given to areas with relatively flat coasts.</p>