Abstract: With the gradual expansion of sponge city construction, pilot projects at the provincial and regional levels have been carried out in county towns, and sponge city planning for county towns has attracted attention. At present, the construction of sponge cities in county towns mostly adopts the idea of large and medium cities but lacks the idea, method, and technology system based on the characteristics of county background. In April 2021, the three ministries and commissions jointly issued ‘The Notice on the Development of Systematic and Global Promotion of Sponge City Construction Demonstration Work’, proposing the construction of sponge cities in a systematic way. Based on the theoretical research on sponge city construction of existing county towns, this paper discusses the key technologies of sponge city construction of county seats based on the basic characteristics of county seats and the practice of related projects, aiming to provide references for county town sponge construction based on the systematic and global promotion vision.