<p>This study examines the dynamics of interaction, competition, and cooperation among cities within the Hohhot-Baotou-Ordos-Yulin Urban Agglomeration (HBOYUA) in Western China. Utilizing ecological niche theory, ecological niche overlap theory, the inter-city gravity model, and social network analysis, this research establishes a multidimensional ecological niche assessment system. This innovative integration of theoretical frameworks and analytical models facilitates a comprehensive and quantitative investigation of competitive-cooperative relationships among the cities. Results from 2007 to 2019 indicate a growing trend in resource allocation similarity, functional roles, and development patterns among these cities, leading to heightened direct competition. Significant competitive relationships were observed between city pairs such as Dalat Banner and Otok Banner, and Tumed Left Banner and Otok Banner. Simultaneously, potential cooperative opportunities were identified between pairs like Huimin District and Yuquan District, and Kundulun District and Jiuyuan District. The study highlights the critical need to balance competition with cooperation and offers policymakers and scholars targeted insights by identifying ecological niche hot and cold spots. Additionally, social network analysis has revealed complex patterns of cooperation and competition within the agglomeration, contributing to the theoretical foundation for collaborative development and strategic urban planning. Further research is recommended to explore the role of urban agglomeration at broader national and regional levels, enriching the understanding of strategic positioning and development in urban agglomerations.</p>