Objective: To search for specific metabolites in the lungs of pneumonia rats fed with a high-calorie diet, as well as explore the changes in the lung metabolites of young rats treated with Yinlai Decoction (YD) and its effects on inflammation-related metabolic pathways.Methods: Lipopolysaccharides (LPS) and a special high-calorie diet were used to induce Sprague Dawley (SD) rats to simulate the intestinal state of infant pneumonia. Liquid chromatography-mass spectrometry technology (LC-MS/MS) was used to detect metabolites in each group. Supervised orthogonal partial least squares discriminant analysis (OPLS-DA) model values were used for the detection results to find the differential metabolites. The metabolic pathways that are involved with the differential metabolites were clarified through enrichment analysis and topological analysis. Finally, the T cell receptor signaling pathway (TCR) signal conversion was analyzed by the network pharmacology method. Results: In the high-calorie diet combined with pneumonia group (M3), a total of 55 metabolites were determined to be different from the normal group (N). A total of 36 metabolites were determined to be different from those in the lung metabolites of the YD treatment group (T1). YD had a regulatory effect on glutathione metabolism, arginine and proline metabolism, ascorbic acid and aldehyde metabolism and phenylalanine metabolism. And the small molecule metabolites could act on the FYN and lymphocyte-specific protein tyrosine kinase (LCK) target proteins in the TCR signaling pathway, thereby affecting the immune function of the lungs. Conclusion: A high-calorie diet can cause abnormal sphingolipid metabolism in the lungs of young rats, thereby creating chronic lung inflammation in young rats. YD has a beneficial effect when used to treat young rats with LPS-induced pneumonia fed on high-calorie diets. Its mechanisms of action may affect the body's immune pathways by regulating the oxidative stress pathway affected by glutathione metabolism.