Abstract: Objective To investigate the values of serum procalcitonin (PCT), anti-thrombin Ⅲ (AT-Ⅲ), D-dimer (D-D), fibrinogen (FIB), thrombin time (TT), activated partial thromboplastin time (APTT), and prothrombin time (PT) in the early diagnosis of pediatric sepsis. Methods A total of 82 children with sepsis in the Pediatric Intensive Care Unit (PICU) of General Hospital of Hunan University of Medicine from June 2020 to June 2023 were selected as sepsis group. Meanwhile, 90 children with respiratory tract infections in the general ward were included in general infection group, and 100 healthy children in the Department of Pediatric Health were selected as control group. The levels of serum PCT, AT-Ⅲ, D-D, FIB, TT, APTT and PT were compared among the three groups. Results Compared with the general infection group and the control group, the sepsis group had significantly higher serum PCT and D-D levels, prolonged TT, APTT and PT in the four-items of coagulation test, and reduced AT-Ⅲ and FIB levels (P<0.05). The areas under the curve (AUCs) for the diagnosis of pediatric sepsis by serum PCT, AT-Ⅲ, D-D, PT, APTT, TT and FIB levels were 0.949, 0.174, 0.911, 0.869, 0.855, 0.834 and 0.242 respectively; among these indexes, serum PCT showed the highest diagnostic value, with the maximum Youden index at a cut-off value of 0.62 μg/L, and the diagnostic sensitivity and specificity were 86.6% and 79.0% respectively. The AUC for the combined diagnosis of pediatric sepsis by the seven indicators was 0.966. Conclusion The detection of serum PCT, AT-Ⅲ, D-D and four items of coagulation test is of great value in the early diagnosis and differential diagnosis of pediatric sepsis.