ASA classification is generally divided into six grades: ASA 1 is a healthy patient who can tolerate surgical anesthesia; ASA 2 is a patient with mild systemic disease and no functional impairment who can tolerate surgical anesthesia; ASA 3 is a patient with severe systemic disease and some functional impairment, but can still tolerate anesthesia; ASA 4 is a patient with severe systemic disease and a lifelong need for uninterrupted treatment with anesthesia The risk is great and requires adequate and meticulous preanesthetic preparation; ASA grade 5 is a patient who is dying and is unlikely to survive within 24 hours, regardless of surgery; ASA grade 6 is a patient who is brain dead. This is the grading of the American Society of Anesthesiologists’ situation assessment, and the “E” or “emergency” should be added to the assessment of emergency surgery: Grade 1 and 2 patients generally tolerate anesthesia well, and anesthesia passes smoothly; Grade 3 patients are at some risk of receiving anesthesia. The level 4 and 5 patients have a greater risk of anesthesia and need adequate and careful preparation before anesthesia.