Background: Capsaicin is commonly used as a flavoring and a riot control agent. However, long-term exposure or high doses can cause acute lung injury in military and police personnel. The mechanisms underlying capsaicin-induced pulmonary toxicity remain unclear. Therefore, this study investigated the molecular mechanisms involved in capsaicin-induced acute lung injury using C57BL/6N mice. Methods: Through both transcriptomic and proteomic analyses of mouse lung tissue, we identified the involvement of the TNF signaling pathway in capsaicin-mediated acute lung injury. Next, we explored the role of TNF signaling in the progression of acute lung injury to identify potential therapeutic targets. In a capsaicin-induced acute lung injury mouse model and A549 cells, we assessed the therapeutic potential of the TNF-α antibody Nerelimomab. Compared with the control group, TNF-α up-regulation was observed, which correlated with increased pathological changes and elevated IL-6 (p < 0.01) and IL-18 (p < 0.01) levels, both in vivo and in vitro. Results: Flow cytometry revealed that compared to the capsaicin group, Nerelimomab treatment reduced the number of capsaicin-induced apoptotic cells (p < 0.001) and was associated with an increased Bcl-2/Bax ratio (p < 0.01) and reduced cleaved caspase 3 expression (p < 0.001). Analysis of A549 cells treated with capsaicin and Nerelimomab corroborated these results. These findings confirm the involvement of the TNF signaling pathway in capsaicin-induced acute lung injury and the apoptosis of alveolar epithelial cells. Conclusions: In conclusion, capsaicin inhalation can cause acute lung injury, and targeting the TNF signaling pathway offers a promising therapeutic strategy. Nerelimomab demonstrates significant potential in alleviating acute lung injury by inhibiting inflammatory mediator release and diminishing apoptosis. Based on transcriptomic and proteomic analyses, this study highlights the crucial role of the TNF signaling pathway in capsaicin-induced acute lung injury and supports the therapeutic efficacy of Nerelimomab in reducing epithelial apoptosis.