Endometritis in dairy cows significantly impacts their reproductive performance. However, its underlying mechanisms remain unclear. Hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunit-alpha (HADHA) is known to regulate the occurrence of various diseases, but its role in bovine endometritis is poorly understood. In the present study, an in vitro bovine endometrial epithelial cells (BEECs) inflammation model was constructed to explore the effects of HADHA on inflammation, proliferation, and apoptosis. Functional analyses based on HADHA interference and overexpression revealed that it positively regulated the expression of IL-6, IL-8, and IL-1β in lipopolysaccharide (LPS)-induced BEECs, enhancing reactive oxygen species (ROS) production and promoting inflammation. Concurrently, HADHA decreased the expression of PCNA, CDK2, and CDK4, inhibited mitotic transition of BEECs from S to G2 phase, and negatively regulated BEEC proliferation. It also increased BAX and Caspase-3 expression while decreasing BCL2 expression, hence promoting BEECs apoptosis. Transcriptomic and metabolomic analyses indicated that HADHA modulated inflammation in BEECs by affecting pathways such as the TGF-beta signaling pathway, fatty acid metabolism, and p53 signaling. These findings provide novel insights into HADHA's role in bovine endometritis and reveal future research directions on its regulatory mechanisms.