To investigate the expression of serum thioredoxin-1 (Trx-1) in sepsis induced acute kidney injury (AKI) and its diagnostic value. Methods A total of 216 patients with sepsis were admitted to the Department of Critical Care from January 2015 to December 2021 in our Hospital. According to the KDIGO guidelines on the diagnosis and grading of AKI in 2012, 85 patients were diagnosed with AKI (38 cases of AKI grade 1, 27 cases of AKI grade 2, 20 cases of AKI grade 3), which was defined as AKI group; 131 cases without AKI were diagnosed with non-AKI group. The serum Trx-1 expression level and clinical data of the two groups were detected and compared, and the risk factors of septic patients complicated with AKI were analyzed by logistic regression. ROC curve was used to analyze the diagnostic value of serum Trx-1 in patients with sepsis associated AKI. Results The incidence of AKI in sepsis patients was 39.35%. The expression level of serum Trx-1 in AKI group was higher than that in non-AKI group, and the difference was statistically significant. The expression level of serum Trx-1 was positively correlated with APACHEII, SOFA score, the proportion of baseline serum creatinine(Scr), lactic acid and AKI ≥ grade 2, and negatively correlated with GCS score and eGFR level. Logistic regression analysis showed that the level of serum Trx-1 was an independent risk factor for septic patients with AKI, and the ROC curve suggested that the level of serum Trx-1 and Scrwere highly specific and sensitive for the diagnosis of septic patients with AKI. 〖WTHZ〗Conclusion In patients with sepsis complicated with AKI, the expression level of serum Trx-1 is higher than that in patients without AKI, which is an independent risk factor for AKI in sepsis patients. It has a high diagnostic value for the diagnosis of sepsis induced AKI. It can be used as a biological marker for the diagnosis of sepsis induced AKI