The 14th Five-Year Plan for China proposes to promote the urbanization process from a county perspective, presenting an unprecedented opportunity to develop county urbanization. However, in the context of relatively limited resources, insufficient funds, and comparatively lower land values in Chinese counties, how to promote county urbanization remains the primary challenge, which has not been studied yet. This study first analyzes the necessity of promoting county urbanization from four dimensions: national development strategy, industrial policy development, local government status, and enterprise development demands using literature research and survey interviews. Based on field research conducted in 32 counties in China, the strengths, weaknesses, opportunities, and threats (SWOT) analysis is carried out on the county urbanization process in this study. By analyzing the developmental status and challenges of major urban areas, expansion areas of counties, and their surrounding countryside, this paper proposes a “three-level gradient integration” concept for the spatial integration of county urbanization. Furthermore, the mechanism of multi-agent linkage to promote county urbanization was explored based on the theory of urban governance and the characteristics of county urbanization. Subsequently, relying on the analysis of policies, such as land acquisition and integrated land improvement, and adopting modes, such as “Investor + Engineering Procurement Construction + Operation” (investor + EPC + O) and renovate–operate–transfer (ROT), we propose a pathway for promoting county urbanization through the linkage of government, enterprises, and residents. This study provides insight into promoting the county urbanization process. Additionally, each country faces the common issue of how to use limited resources to promote regional development, and this article can provide valuable insights and inspiration for addressing this shared issue by the principle of adapting to local conditions and adhering to the concept of efficient market and proactive government.