Background: Radiation-induced lung injury (RILI) is a common complication of thoracic tumor radiotherapy, and its occurrence limits the choice of anti-tumor therapy and reduces the quality of life of patients. Qingdi Mixture (QDM) is a traditional Chinese medicine decoction commonly used in preventing RILI during tumor radiotherapy in the Affiliated Hospital of Qingdao University. However, its main components and potential mechanisms of action remain unclear. Objective: In this study, Liquid Chromatograph Mass Spectrometer analysis and network pharmacology were used to study the molecular mechanism of QDM in treating radiation lung injury. Methods: The main active components of QDM were detected by LC-MS analysis, drug-related targets were retrieved by the TCMSP database, and RILI-related targets were retrieved by the GeneCards database. Component-target-pathway network and protein-protein interaction (PPI) networks were constructed using Cytoscape software. The potential signaling pathways of QDM for RILI were discussed by GO and KEGG enrichment analysis. Finally, core components binding to key targets were verified by molecular docking. Results: Eventually, 57 major active components were identified in QDM and 1,549 RILI-related targets were retrieved. The core targets of the PPI network were mainly closely related to inflammation and transcriptional regulation. GO and KEGG enrichment analyses indicated that the NF-κB, JAK-STAT, and Necroptosis signaling pathways might play key roles in the treatment of RILI by QDM. Meanwhile, molecular docking showed that the core active components of QDM had stable binding to the main targets of RILI. Conclusion: QDM prevents and treats RILI through multi-target and multi-pathway, but further experimental verification is needed.