Objective: To investigate the coagulation function indicators and identify influence factors of hypercoagulability in patients with adrenocorticotropic hormone (ACTH) independent Cushing syndrome (CS). Methods: In our retrospective study, the electronic medical records system of Peking University First Hospital was searched for the patients diagnosed with ACTH independent CS on discharge from January 2014 to June 2019. Nonfunctional adrenal adenoma patients were chosen as control group and matched 1 ∶1 by body mass index (BMI), gender, and discharge date. Clinical features and coagulation function indicators were compared between the two groups. Results: In the study, 171 patients were included in each group. Compared with control group, activated partial thromboplastin time (APTT), and prothrombin time (PT) in ACTH independent CS group were significantly lower [(29.22±3.39) s vs. (31.86±3.63) s, P < 0.001; (29.22±3.39) s vs. (31.86±3.63) s, P < 0.001], and both D-dimer and fibrin degradation products (FDP) levels were significantly higher (P < 0.05). Percentage of APTT levels under the lower limit of reference range in the CS patients was significantly higher than that in nonfunctional group (21.6% vs. 3.5%, P < 0.001). Percentage of D-dimer levels over the upper limit of reference range in the CS patients was significantly higher than that in nonfunctional group (13.5% vs. 6.6%, P=0.041). There were three patients with deep venous thrombosis and one patient with pulmonary embolism in CS group, however none was in control group. The area under curve (AUC) of serum cortisol rhythm (8:00, 16:00 and 24:00) levels was negatively associated with the levels of PT (r=-0.315, P < 0.001) and APTT (r=-0.410, P < 0.001), and positively associated with FDP (r=0.303, P < 0.001) and D-dimer levels (r=0.258, P < 0.001). There were no differences in coagulation function indicators among different histopathologic subgroups (adrenocortical adenoma, adrenocortical hyperplasia, oncocytic adenoma, adrenocortical carcinoma). With Logistic regression analysis, the AUC of cortisol and glycosylated hemoglobin A1c (HbA1c) levels were independent risk factors for hypercoagulability in the ACTH independent CS patients (P < 0.05). Conclusion: ACTH independent CS patients were more likely in hypercoagulable state compared with nonfunctional adrenal adenoma, especially in ACTH independent CS patients with higher levels of cortisol AUC and HbA1c. These patients should be paid attention to for the hypercoagulability and thrombosis risk.