Inclusion Criteria:Voluntary acceptance;Asa1-2 level;Age 18-95y;Mallampati grades Ⅰ or Ⅱ

Exclusion Criteria:

1. Patients with blood clotting disorders or a tendency to oropharyngeal bleeding, mucosal damage or space occupation, difficulty in placing oropharyngeal airway, etc., who cannot perform oropharyngeal airway ventilation;
2. Severe cardiac insufficiency (<4mets);
3. Patients with severe renal insufficiency (requiring dialysis before surgery);
4. Diagnosed severe liver insufficiency;
5. Diagnosed with chronic obstructive pulmonary disease (COPD) or currently suffering from other acute or chronic lung diseases, requiring long-term or intermittent oxygen therapy;
6. Increased intracranial pressure;
7. Upper respiratory tract infections such as mouth, nose or throat;
8. Fever (core body temperature >37.5 degrees Celsius);
9. a confirmed diagnosis of pregnancy or breastfeeding;
10. Allergic to sedatives such as propofol or equipment such as tape;
11. Emergency surgery;
12. Multiple trauma;
13. SpO2 < 95% in preoperative breathing air;