Objective To investigate the risk factors of chronic obstructive pulmonary disease (COPD) combined with obstructive sleep apnea (OSA) and its relationship with apnea-hypopnea index (AHI). Methods Clinical data of 216 COPD patients with OSA were retrospectively chosen in the period from January 2016 to December 2019 in our hospital. All patients were divided into different groups according to with or without OSA and the clinical features of patients with and without OSA were compared. Multivariate analysis was used to analyze the influencing factors of COPD with OSA and the correlation between AHI and COPD with OSA was also evaluated. Results ① The age, body mass index (BMI), neck circumference, smoking index, forced expiratory volume in 1 second (FEV1), FEV1% predicted (FEV1pred), the ratio of FEV1 to the forced vital capacity of the lungs (FEV1/FVC), COPD assessment test (CAT) score, Epworth sleepiness scale (ESS) score, Charlson comorbidity index (CCI) score, sleep apnea clinical score (SACS) score and proportion of patients with essential hypertension in OSA group were significantly higher than non-OSA group (P<0.05). The course of disease and the proportion of severe COPD and GOLD grade 4 in OSA group were significantly less than non-OSA group (P<0.05). ② AHI was positively correlated with age, BMI, neck circumference, smoking index, FEV1%pred, FEV1%pred<50%, CAT score, ESS score, CCI score and SACS score (P<0.05); and negatively correlated with FEV1%pred<50% (P<0.05). ③ Multivariate analysis showed that BMI, FEV1%pred<50%, CAT score and ESS score were the independent factors of COPD patients with OSA (P<0.05). ④ The proportion of AHI<5 times/h in GOLD grade 4 was significantly higher than GOLD grade 1-3 (P<0.05). The proportion of AHI> 30 times/h in GOLD grade 4 was significantly lower than GOLD grade 1-3 (P<0.05). Conclusion The incidence of COPD with OSA was independently correlated with BMI, FEV1%pred, CAT score and ESS score; patients with severe COPD possess lower OSA risk.