The objective of this study was to observe the relationship between levels of family environmental tobacco smoke (ETS) and obstructive sleep apnea hypopnea syndrome (OSAHS). Clinical datr AHI, lower oxygen saturation, longer apnea time, and lower ventilation time (p < 0.05). There was a correlation between EST and OSAHS. Compared with non-exposa of 209 patients who visited the respiratory department were retroactively collected. The data entailed gender, age, body mass index (BMI), family environmental smoke exposure, medical history, Epworth sleepiness scale (ESS) score, and polysomnography (PSG) indicators. Two groups of patients were studied: ETS-exposed group and non-ETS-exposed group. Using the apnea hypopnea index (AHI), OSAHS patients were classified as mild (5 <= AHI <= 15), moderate (15 < AHI <= 30), and severe (AHI > 30). There were 148 cases in the OASHS group and 61 cases in the normal group. 56.66% of the OASHA group were ETS-exposed patients, which was significantly higher than that the normal group ETS-exposure of 31.57% . Compared to the OSAHS patients unexposed to ETS, the OSAHS patients with EST exposure had a greater degree of lethargy, greateed, the EST-exposed group was more susceptible to OSAHS, and the longer the time, the more severe the condition.