To analyze the value of arterial blood lactate (Lac), procalcitonin (PCT) combined with quick sequential organ failure score (qSOFA) in evaluating the condition of patients with sepsis. Methods A retrospective study was conducted on 248 sepsis patients admitted to the ICU of our hospital from January 2019 to June 2021. According to the severity of the disease, they were divided into sepsis group (210 cases) and sepsis shock group (38 cases).The differences in Lac, PCT, qSOFA scores and Lac, PCT combined qSOFA scores and other indicators were compared between the two groups of patients. Through univariate and multivariate logistic regression methods and drawing receiver operating characteristic (ROC) curve, the value of each indicator in evaluating the condition of patients with sepsis was comprehensively explored. Results The median value of Lac in sepsis shock group was 39 mmol/L, which was significantly higher than 1.9 mmol/L in sepsis group (Z=1.314, P＜0.001). The median value of PCT in sepsis shock group was 9.17ng/mL, which was significantly higher than 1. 99ng /mL in sepsis group (Z=-3.716, P＜0.001 ). The median value of qSOFA scores was significantly higher in the sepsis shock group (2 points) than in the sepsis group (1 point) (Z=-6.120, P＜0.001), and the differences were statistically significant (all P＜0.001). After multivariate logistic regression analysis, it was found that the history of diabetes, Lac (OR=1.410, 95% CI:1.196-1.662), PCT (OR=1.016, 95% CI:1.001-1.032) and qSOFA scores (OR=6.710, 95% CI:2.534-1.032) 17.773) were independent risk factors affecting the severity of sepsis (all P＜0.05). The area under the curve (AUC) of Lac, PCT combined with qSOFA score for predicting the severity of sepsis was 0.907, which was greater than the AUC of single index and the AUC of pairwise combination, with sensitivity and specificity of 84.2% and 86.2%, respectively. Conclusion The predictive performance of Lac, PCT combined with qSOFA score in predicting septic shock is better than that of single index and pairwise combination.