Abstract: With the promotion of the "dual carbon" goal and the demand for industrial upgrading, traditional power companies need to build low-carbon and automated process sections within their existing factory areas, and provide corresponding power supply and grounding systems. Taking the newly added carbon capture (CCUS) process section in a thermal power plant as an example, this paper systematically and comprehensively elaborates on the grounding system design for its supporting 10kV distribution room and process production area. The design fully combines the actual situation of the existing 220kV main grounding grid in the factory area, adopts a layered and partitioned grounding strategy, and proposes a comprehensive design scheme for independent grounding grid construction, equipotential grid extension, and multi-path main grid interconnection. The focus is on the selection of grounding grid structural parameters, calculation and control of grounding resistance, equipotential bonding measures in process areas, and key points of interconnection technology between new and old grounding systems. The scheme has been implemented and tested on site, and the grounding resistance meets the requirements of GB 50065-2011. The grounding potential balance of the entire plant is good, providing a complete and reliable technical path for the design of grounding systems for similar plant expansion projects.