Danggui Jixueteng decoction (DJD) has been used to treat anemia for many years and has been shown to be effective. However, the mechanism of action and effective components are yet unknown. We want to search for pharmacodynamic components in DJD with therapeutic effects on myelosuppression after chemotherapy (MAC), utilizing a spectrum-effect connection study based on gray relational analysis and partial least-squares regression analysis. Transcriptome sequencing (RNA-Seq) was used to investigate the mechanism by which DJD treats MAC. In this study, fingerprints of different batches of DJD (S1-S10) were established by ultraperformance liquid chromatography-mass spectrometry (UPLC-MS), after which the resulting shared peaks were screened and identified. A total of 21 common peaks were screened through the fingerprints of different batches of DJD, and the similarity of each profile was greater than 0.92. The 21 shared peaks were identified by comparison with the standard sample and searching on a MassLynx 4.1 workstation. The rat model of MAC was established by intraperitoneal injection of cyclophosphamide, and DJD treatment was carried out in parallel with the establishment of the model. White blood cell count, red blood cell count, platelet count, interleukin-3, hemoglobin concentration, granulocyte-macrophage colony-stimulating factor, and nucleated cell count were used as efficacy indicators. Pharmacodynamic results indicated that DJD could effectively improve the pharmacodynamic indices of MAC rats. The results of gray relational analysis demonstrated eight peaks with high correlation with efficacy, which were 2, 7, 10, 14, 15, 16, 18, and 21, and the partial least-squares regression analysis showed four peaks with variable importance in projection values greater than 1, which were 10, 12, 13, and 19. RNA-Seq was used to identify DEGs in rat bone marrow cells, Gene Ontology functional enrichment and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of DEGs were performed. The genes related to the effects of DJD on MAC were mainly involved in the phosphatidylinositol 3-kinase/serine-threonine kinase (PI3K-Akt) signaling pathway, the mitogen-activated protein kinase signaling pathway, actin cytoskeleton regulation, focal adhesion, and Rap1 signaling pathways. The results of the RNA-Seq study were confirmed by a qPCR experiment. The effective compounds of DJD against MAC include albiflorin, paeoniflorin, gallopaeoniflorin, salvianolic acid H/I, albiflorin R1, salvianolic acid B, salvianolic acid E, benzoylpaeoniflorin, and CHNO. The mechanism by which DJD prevents and treats MAC might involve the control of the PI3K-Akt signaling pathway.