This study uses cyclopropofol as a positive control and adopts a large sample, multicenter, randomized, single-blind, positive parallel control test design to explore the clinical application value of cyclopropofol in preventing postoperative nausea and vomiting.

Before the end of the anesthesia maintenance period/operation, it was divided into groups A, B and C according to different drug regimens. The subjects were randomly assigned to one of them in a 1:1:1 ratio to receive cyclopophenol or sevoflurane anesthesia. Each group of subjects should be roughly consistent according to the proportion of each number of PO . After screening the object, the researchers of each testing center are confirmed by the researchers of the center, log in to the random system, fill in the screening information, obtain the random number information, and distribute the corresponding research drugs according to the random number. The number of random shelters is generated through SAS software, which is used as a centralized random grouping system to import the total number of drugs. This study sets up evaluation researchers and drug management researchers. The whole experimental process turned a blind eye to not only the subjects, but also the evaluators. This study has set up evaluation investigators and administrative investigators. Administrative researchers are only involved in the random grouping, dispensing and delivery process. Other processes, including the subject's informed consent, screening, efficacy indicators and safety evaluation, and planned visits, are completed by the evaluation investigators.

Inclusion Criteria:

1. At least 2 of the 4 induced risk factors of PONV (risk factors are: history of PONV or motion sickness, habitual non-smoking, women, receiving opioid analgesia).
2. For patients with an estimated duration of anesthesia ≥1h and ≤3h (non-emergency, non-cardiothoracic surgery and non-intracranial surgery), laparoscopic surgery, gastrointestinal surgery, obstetrics and gynecology surgery, tympanoplasty, tonstonectomy, etc., are preferred. The duration of hand anesthesia was defined as the period from the beginning of anesthesia induction to the end of anesthesia maintenance
3. Male or female, age ≥ 18 years old, ASA-PS score I to III.

Exclusion Criteria:

1. There is a history of vestibular nerve disorder or dizziness or nausea and vomiting 24 hours before the operation; or receiving conventional antiemetic treatment.
2. The subjects who need to maintain ventilation after surgery or need to place the nasogastric tube in place for a period of time.
3. The subject who the researcher believes that there are any other factors that are not suitable to participate in the research.