Grounding electrode is an important part of the DC transmission project. Traditional grounding electrode occupies a large area, causing us extremely difficult to select the site and perform requisition of lands. China Southern Power Grid proposes a technical route to solve the problem by constructing a deep-well grounding electrode, and carries out a demonstration project construction of deep-well grounding electrode. Based on the practice of the demonstration project, this paper studies the influence on the grounding temperature rise of the deep well by the length of the single electrode of the grounding electrode, the total number of parallel electrodes, the buried depth of the grounding electrode, the spacing of the electrodes, and the diameter of the filled coke. The results show that the above-mentioned five factors can cause changes in the grounding overflow density, which affects the overall temperature rise of the grounding electrode and the maximum temperature rise. The temperature rise shows a trend of decreases with the increase of the length of a single electrode, or the total number of parallel electrodes, or the cross-sectional area of coke, but the trend of decrease tends to be gradual. The buried depth of the grounding electrode needs to be selected according to the stratification of the soil at the electrode site. Choosing a suitable buried depth where the soil layer has low and relatively even resistivity, is beneficial to reduce the temperature rise of the grounding electrode. the spacing of the electrodes is related to the land occupied by the electrode site, but due to the limitation of the construction technique of deep well drilling, the electrode spacing cannot be too small.