Abstract: Located in the mountainous regions of southwestern Fujian, the Hakka Tulou settlements are not only products of traditional agrarian culture but have also been reshaped by modern influences from Overseas Chinese. Drawing on genealogical records, local chronicles, and field oral histories as corroborative sources, this article examines three representative landscape transformations in the Deyuantang Clan Settlement of Nanjing County, Zhangzhou: the architectural shift from rectangular to circular Tulou structures, the construction of Qujiang Market, and the development of commemorative infrastructure incorporating ceremonial stone flagpoles, pavilions, bridges, and roads. It analyzes the integration of Overseas Chinese culture across three dimensions: the fengshui landscapes of traditional settlements, the transnational social-life landscapes of the modern era, and contemporary diasporic commemorative landscapes. The study reveals how the mountainous hometowns of Overseas Chinese actively assimilated and transformed this cultural influence to reinforce local agrarian traditions, thereby demonstrating the historical contributions of Overseas Chinese to the sustainable evolution of Fujian's Tulou settlements as living heritage.