Objective To observe the effect of end-tidal carbon dioxide partial pressure (PetCO-2) monitoring in postoperative extubated patients during emergence from general anesthesia. Methods A total of 320 postoperative patients who were transferred to the post-anesthetic care unit (PACU) after extubation were randomly and evenly divided into 2 groups. The control group received routine oxygen inhalation through a single-hole nasal catheter at 3 L/min, and was subjected to continuous monitoring of ECG, respiration, non-invasive blood pressure and SpO-2. On top of these measures, continuous PetCO-2 monitoring was added to the intervention group. The incidence rate of hypoxemia, the detection rate of hypercapnia and apnea, the frequency of mask pressurization and the recovery time were compared between the two groups. Results The severity of hypoxemia, the rate of mask pressurization in the intervention group were significantly lower than those in the control group; the detection rates of hypercapnia and apnea in the intervention group were significantly higher than those in the control group; the emergence time in the intervention group was significantly shorter than that in the control group (P＜0.05, P＜0.01). Conclusion The application of PetCO-2 monitoring in postoperative patients after extubation during general anesthesia recovery period can detect respiratory abnormalities such as apnea and hypercapnia in time, reduce the incidence of hypoxemia, improve the safety of the anesthesia recovery period and shorten the recovery time.