<p>As a carrier of China’s historical and cultural heritage, the sustainable development of the integration of agriculture, culture, and tourism (Agri-Culture-Tourism) in the old revolutionary base areas plays an important role in promoting the protection of cultural heritage and regional economic growth. However, how to achieve sustainable development of Agri-Culture-Tourism integration in old revolutionary base areas and what the key factors influencing such development are still remain important research topics that have not been explored in depth at present. This paper explores the practices and explorations of Tianshui City, a revolutionary old area, in terms of sustainable development in Agri-Culture-Tourism. Through methods such as Python Grey Relational Analysis, Logistic Regression Analysis, and Principal Component Factor Analysis, this study reveals the high correlation between Agri-Culture-Tourism and the tertiary industry in Tianshui City. It identifies key factors influencing tourists’ willingness to support, including the “level of infrastructure development for Agri-Culture-Tourism,” “richness of Agri-Culture-Tourism resources,” and “integration of Agri-Culture-Tourism supporting poverty alleviation.” Tianshui city has made remarkable achievements in promoting the sustainable development in Agri-Culture-Tourism, which requires focusing on promoting the development of secondary service industry, basic service industry and improving the efficiency of publicity. This study innovatively reveals effective experiences in the sustainable development of Agri-Culture-Tourism in revolutionary old areas, providing valuable insights for the sustainable development of similar regions in China and other developing countries.</p>