This article explores the core question of how many plants can fit in a high-density indoor grow room, offering an in-depth analysis of the dynamic balance between space utilization, light distribution, airflow, irrigation, and nutrient management, as well as plant selection. It emphasizes that high-density growing is not simply about increasing plant numbers, but about maximizing yield per unit area through scientific design and precise management. Drawing on practical examples, the article highlights that only by optimizing environmental conditions and cultivation systems can growers achieve stable, efficient, and sustainable production within limited indoor spaces.