Objective: To investigate the mechanism of action of Wuzi Yanzong pill (WYP) in rats with oligoasthenozoospermia (OAZ) via metabolomics and to provide a possible basis for improving this WYP-based treatment. Methods: A rat model of OAZ was established by treating male Sprague–Dawley rats with glucosides from Tripterygium wilfordii Hook. F. Seventy-two rats were randomly divided into six groups: control, L-carnitine (positive control), model, and low-, medium-, and high-dose WYP groups. Rats in the experimental groups were treated with WYP for 4 weeks. At the end of the treatment period, sperm cell quality (density, motility, and viability) was assessed using a semen analysis system, mitochondrial membrane potential (MMP) was assessed using flow cytometry, and testicular injury was assessed using hematoxylin and eosin staining to validate the therapeutic effect of WYP in OAZ. Further, serum metabolomics-based analysis was performed using high-performance liquid chromatography-mass spectrometry to identify differential metabolic pathways and possible mechanisms of action of WYP in OAZ treatment. Results: A rat model of OAZ was considered successfully-established after comparing the quality of spermatozoa in the model group to that in the control group. WYP-M and WYP-H treatments significantly improved sperm cell density, motility, and viability compared with those in the model group (all P < .05). Compared with the model group, both WYP-M and WYP-H treatments increased MMP values (P = .006 and P = .021 respectively), while there was no significant difference in the L-carnitine group. L-carnitine and WYP administration reversed damage to the testes to varying degrees compared with that in the model group. Further, 44 differential metabolites and four metabolic pathways, especially autophagy pathway, related to OAZ were identified via metabolomics. Conclusions WYP improves sperm cell quality and MMP in OAZ primarily via autophagy regulation. These findings can be employed to improve the efficacy of WYP in humans.