Objective: To investigate the clinical characteristics and risk factors of severe acute pancreatitis (SAP) combined with invasive fungal infections (IFI). Methods: The clinical data of 84 SAP patients admitted from January 2019 to December 2021 were retrospectively analyzed and divided into the IFI group (25 cases) and the non-IFI group (59 cases) according to whether or not IFI infection occurred. The types and sites of fungal infections in patients in the IFI group were analyzed, and the clinical differences between the IFI and non-IFI groups were compared and analyzed by logistic regression. Results: There were 25 patients among the 84 SAP patients combining with IFI, with an incidence of 29.76%. 8 cases of death occurred in these patients, with a mortality rate of 32.00%. A total of 31 fungal strains were detected in pathogenetic examination, all of which were Candida. Among them, 15 strains of Candida albicans (48.40%), 6 strains of Candida near-smooth (19.35%), 6 strains of Candida smooth (19.35%), 2 strains of Candida tropicalis (6.45%), and 2 strains of Candida kriegerii (6.45%) were detected. The sites of IFI in SAP patients were lung (80.64%), abdominal cavity (6.45%), blood (6.45%), biliary tract (3.23%), and intestine (3.23%). The results of univariate analysis showed that the combination of IFI in SAP patients was associated with age, lymphocyte count (×10⁹/L), procalcitonin(PCT) (ng/mL), multiple organ dysfunction syndrome (MODS), shock, APACHE II score, total parenteral nutrition (TPN) time (d), antibiotic using time (d), number of types of antibiotics used, indwelling time of urinary catheter (d), indwelling time of deep venous catheter (d), mechanical ventilation time (d) and length of ICU stay(h). Multivariate analysis results showed that age, PCT, indwelling time of deep venous catheter (d), mechanical ventilation time (h), and length of ICU stay (h) were independent risk factors of SAP patients complicated with IFI (P＜0.05). Conclusion: The strain distribution of SAP combined with IFI was mainly candida albicans, and the main site of prevalence was the lungs. Age, PCT, duration of deep venous catheterization, mechanical ventilation time, and length of ICU stay were independent risk factors for SAP patients complicated with IFI.