To evaluate the efficacy and safety of ciprofol for the induction of general anesthesia in obese patients undergoing laparoscopic sleeve gastrectomy. A randomized, parallel, propofol injection positive control study will be conducted to select obese patients who will undergo laparoscopic sleeve gastrectomy in the author's hospital. To evaluate the efficacy and safety, the main observation index, secondary observation indexes, safety evaluation indexes, and the incidence of postoperative adverse reactions will be recorded and compared between the two groups.

To evaluate the efficacy and safety of ciprofol for the induction of general anesthesia in obese patients undergoing laparoscopic sleeve gastrectomy. A randomized, parallel, propofol injection positive control study will be conducted to select obese patients who will undergo laparoscopic sleeve gastrectomy in the author's hospital. To evaluate the efficacy and safety, the following indexes will be recorded and compared between the two groups.

• The main observation index：(1) The rate of successful anesthesia induction
• Secondary observation indexex：(1) Time from initial administration of study drug to loss of consciousness; (2) Time from initial administration of study drug to disappearance of eyelash reflex; (3) Changes in bispectral index(BIS) values during anesthesia induction
• Safety evaluation indexes：(1) Adverse events; (2) Intubation response rate; (3) Vital signs; (4) Evaluation of injection pain
• Adverse events to be focused on：(1)The incidence of blood pressure reduction requiring treatment during anesthesia induction; (2) The incidence of respiratory depression

Inclusion Criteria:

• 18 < age ≤ 65, regardless of gender;
• ASA is classified as grade I-III;
• BMI≥35kg/m2
• Obese patients who need laparoscopic sleeve gastrectomy under general anesthesia;
• The subjects voluntarily participated in the trial and signed the informed consent.

Exclusion Criteria:

• Contraindications to general anesthesia;
• Accompanied by infectious heart disease such as myocarditis or endocarditis, septicemia;
• Brain injury, possible intracranial hypertension, cerebral aneurysm, cerebrovascular accident history and central nervous system diseases: mental system diseases (schizophrenia, mania, insanity, etc.) and long-term history of taking psychotropic drugs, or other diseases that hinder the measurement of BIS value;
• Acute heart failure, unstable angina pectoris, myocardial infarction within 6 months before screening, resting ECG heart rate ≤ 50 beats / min, third degree atrioventricular block and other serious arrhythmias, serious heart valve disease, QTc: male ≥ 450ms, female ≥ 470ms;
• Abnormal liver and kidney function (ALT or AST ≥ 2.5 times the upper limit of normal value, TBIL ≥ 1.5 times the upper limit of normal value), abnormal renal function (bun or urea ≥ 1.5 times the upper limit of normal value, cr> the upper limit of normal value, or dialysis treatment within 28 days before operation), or obvious abnormal coagulation function (pt/ aptt/tt higher than the upper limit of normal value), anemia or thrombocytopenia (HB ≤ 90g/l, PLT ≤ 80 × 109/L)
• Those whose blood pressure was not satisfactorily controlled (SBP ≥ 160mmhg and / or DBP ≥ 100 mmHg in sitting position during screening period);
• SBP in sitting position during screening period ≤ 90mmHg;
• Diabetes subjects whose blood glucose was not satisfactorily controlled (fasting blood glucose ≥ 11.1mmol/l in the screening period and / or random blood glucose ≥ 13.6 mmol/l);
• Have a history of drug abuse and alcoholism within 2 years before the screening period. Alcoholism is defined as regular drinking for more than 14 times / week (once =150 ml wine or 360 ml beer or 45 ml spirits);
• The subjects who were judged to have difficulty in respiratory management were rated as grade IV by modified Mahalanobis score;
• Known or suspected allergy or contraindication to various components of the study drug or other benzodiazepines, opioids, propofol, muscle relaxants, etc;
• Pregnant or lactating women or subjects with birth plan within 6 months (including men);
• Those who participated in any clinical trial as subjects within 3 months before enrollment;
• Other circumstances determined by the researcher as unsuitable for inclusion.