In the progression of pneumonia and lung cancer, the imbalance of energy metabolism and immune function gradually reveals significant pathological roles. The research indicates that under chronic inflammatory conditions, inflammatory factors such as interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) are released in large quantities, impairing the functions of T cells and macrophages. This triggers metabolic reprogramming, shifting immune cells from oxidative phosphorylation to glycolysis, leading to an imbalance in energy supply and demand. Additionally, cancerous cells exploit the Warburg effect, preferentially utilizing glycolysis for rapid energy production. They also secrete lactate to modify the microenvironment, suppressing the anti-tumor activity of CD8⁺ T cells. The interplay between metabolic and immune dysfunction significantly increases the risk of carcinogenesis under inflammatory conditions. In Traditional Chinese Medicine (TCM), the concept of “spleen (earth) supporting lung (metal) ” emphasizes the role of spleen in governing transportation and transformation to nourish lung and strengthen lung Qi, thereby enhancing resistance to external pathogens. However, in pathological states, spleen deficiency leads to “earth failing to generate metal”, characterized by impaired spleen function and a lack of nourishment to lung. Modern studies corroborate this perspective, showing that in inflammatory environments, immune cell metabolic dysfunction is exacerbated, while cancerous cells favor high-energy metabolic pathways to meet their growth demands. Furthermore, the interaction between metabolic reprogramming and immune dysregulation is a critical mechanism underlying the transformation of pneumonia into lung cancer. This paper focused on the “metabolism-immune interaction” to deeply explore the manifestations of the “earth failing to generate metal” pathogenesis in the transformation from pneumonia to lung cancer. By analyzing the pathological mechanisms from the perspectives of energy metabolism abnormalities and immune dysfunction, and integrating TCM theories with modern research findings, it aimed to provide novel theoretical foundations and intervention strategies for preventing and managing pneumonia-to-lung cancer transformation. Regulating the balance between metabolism and immunity and adopting the TCM approach of “strengthening earth to support metal” may help delay the progression from pneumonia to carcinogenesis, improve the patients' quality of life, and highlight the unique advantages of TCM in treatment.