Abstract: Introduction The current releasing density is one of the key parameters for the performance of DC vertical earthing electrode. Method Based on the structure characteristics of vertical DC earthing electrode, study of the influence of sub-electrodes number, sub-electrodes length, sub-electrodes gap distance and electrode well section on the current releasing density and its evenness were carried out. Result The study shows that the current releasing density is related to the total length of sub-electrodes, and it is not related to the number of sub-electrodes and the gap distance between them. However, the unevenness of current releasing density is related to the gap distance and the electrode well section. Conclusion Optimized vertical electrode structure is presented according to the study results.