Objective To investigate the early diagnostic value of peroxidase proliferation activated receptor gamma auxiliary material 1 alpha（PGC ⁃1α）for secondary acute kidney injury（AKI）in patients with sepsis. Methods A total of 107 patients with sepsis admitted to the department of critical care medicine of Shaoxing Sec⁃ ond Hospital from October 2019 to January 2022 were selected as the research objects and divided into AKI group （n = 68）and non⁃AKI group（n = 39）according to whether complicating secondary AKI. The baseline clinical data of the two groups were compared. Fasting venous blood and urine samples were collected at the time of diagnosis of sepsis to detect serum PGC⁃1α，procalcitonin（PCT），lactic acid（Lac），creatinine（sCr），neutrophil gelatinase⁃ associated lipocalin（NGAL）levels and estimated glomerular filtration rate（eGFR）. Binary logistic regression analysis was used to analyze the risk factors of secondary AKI in patients with sepsis；Spearman correlate analysis was used to analyze between serum PGC⁃1 α level and other clinical indicators；Receiver operating characteristic （ROC）curve was used to analyze the predictive value of PGC ⁃ 1α level for AKI in patients with sepsis. Results There was no significant difference in age，sex，BMI，combined basic disease history，proportion of primary infection site，and Lac level between the two groups（P > 0.05）. The acute physiology and chronic evaluation Ⅱ （APACHEⅡ）score，sepsis⁃related organ failure assessment（SOFA）score and the levels of PCT，sCr and NGAL in AKI group were significantly higher than those in non ⁃AKI group（P < 0.05）. However，eGFR and PGC ⁃1α were significantly lower than that in non ⁃AKI group（P < 0.05）. Binary logistic regression analysis showed that sCr，NGAL，eGFR and PGC⁃1α were the independent risk factors for secondary AKI in patients with sepsis. Spear⁃ man correlation analysis showed that serum PGC⁃1α level in sepsis patients was negatively correlated with sCr andNGAL（r = -0.302，-0.635，P < 0.05），but positively correlated with eGFR（r = 0.475，P < 0.05）. ROC curve analysis showed that the diagnostic efficacy of serum PGC⁃1α level for secondary AKI in patients with sepsis was better than that of NGAL and eGFR. Conclusion The serum level of PGC⁃1α is significantly increased in the early stage of patients with sepsis secondary AKI，which may be used as an effective predictor for early diagnosis of acute kidney injury caused by sepsis.