Grounding electrode is an important part of HVDC systems, and the determination of design conditions is the key of grounding electrode optimal design. The operational states of grounding electrodes in CSG are researched, and the rules of performance period, number of times and ampere-hour are counted. According to actual running data, the design conditions of conventional grounding electrode are optimized,to effectively reduce the area and cost requirements of conventional grounding electrodes. The concept of short-time grounding electrode conception is proposed, and it’s design conditions are put forward according to engineering operation experience for reducing the difficulty of station site selection and improving the economy of grounding electrodes.