Objective: To explore the inflammation and coagulation levels in patients with chronic obstructive pulmonary disease (COPD) complicated with secondary polycythemia at high-altitude areas. And thus to provide basis for improving the prognosis and the quality of life of patients. Methods: A total of 222 patients with COPD in Qinghai University Affiliated Hospital from January 2016 to September 2019 were selected, including 111 patients with complicated secondary polycythemia as the case group, and 111 patients without complicated secondary polycythemia as the control group. The coagulation related indexes, ESR, CRP and erythrocyte parameters were collected retrospectively during the patients’ hospitalization. The corresponding indexes of the two groups were compared and analyzed. The correlation between inflammation and coagulation indexes in patients with COPD complicated with secondary polycythemia was also analyzed. Results: The prothrombin time of patients with COPD complicated with secondary polycythemia was prolonged and higher than that of the control group, and the difference was statistically significant (P<0.05). In the control group, the levels of D-Dimer, ESR, CRP, and fibrinogen were higher than those in the case group; the fibrinogen content was positively correlated with ESR and CRP; the hematocrit was negatively correlated with ESR. The differences were statistically significant (P<0.05). Conclusion: We should be alert to the risk of hemorrhage caused by the changes of coagulation mechanisms in patients with COPD complicated with secondary polycythemia at high-altitude areas. And we should pay more attention to the changes in inflammation-related indexes of patients. The early and reasonable intervention of inflammation and coagulation level helps to improve the prognosis of these patients.