Acute pancreatitis (AP) is a common emergency in the digestive system, and in severe cases, it can progress to severe acute pancreatitis (SAP), with a mortality rate of up to 30%, representing a dire situation. SAP in mice was induced by l‐arginine (l‐Arg). HE, IHC, WB and ELISA were used to study the role and regulation of HIF1A in SAP. At the same time, QPCR, WB, CHIP‐QPCR and luciferase report were used to explore the specific mechanism of HIF1A regulation of SAP in vitro. The research results indicate that following SAP induction, the pancreatic tissue of mice exhibited significant glycolytic abnormalities, accompanied by a marked upregulation of HIF1A expression. This led to apparent damage in the pancreatic tissue, lungs, and kidneys. However, in sh‐HIF1A mice, the degree of these injuries was significantly alleviated, along with a reduction in the production of inflammatory factors, oxidative products, and lipid peroxidation markers. This suggests that HIF1A plays a crucial role in the inflammatory and oxidative stress processes during SAP. Further exploration revealed that the absence or overexpression of HIF1A affects SAP by inducing ferroptosis through the ACSL4/LPCAT3/ALOX15 pathway. Notably, the elevated lactate level resulting from glycolytic abnormalities further enhances the histone lactylation in the HIF1A promoter region, thereby aggravating the expression of HIF1A. Lactate‐dependent HIF1A transcriptional activation exacerbates severe acute pancreatitis through the ACSL4/LPCAT3/ALOX15 pathway induced ferroptosis.