This paper systematically sorted out the evolutionary trajectory and theoretical basis of land supporting policies for dairy farming in China, and focused on the core restrictive role of the carrying capacity logic in ruminant breeding. Through policy text analysis and empirical literature research, it revealed structural predicaments faced by large-scale dairy farming at present, such as soaring feed costs and difficulties in manure disposal caused by insufficient supporting land. Combined with the cyclical fluctuation characteristics of the current dairy market, this paper demonstrated the vital significance of mandatory supporting forage land in cost reduction, efficiency improvement and industrial resilience enhancement. It was suggested to integrate the carrying capacity logic into the approval system for dairy farm construction, and pilot a rigid linkage mechanism between breeding scale and land area in major northern producing provinces, so as to provide institutional support for the high-quality development of the dairy industry.