Weight loss surgery is a systematic project, which generally consists of three parts: professional pre-operative assessment and education, standardized and individualized surgery, and long-term post-operative health management and nutritional guidance, each of which involves a lot of things and tests the technical level of the medical team performing the surgery. One of the tests that can have a significant impact on the success of the surgery is the sleep and respiratory examination during the preoperative evaluation. Patients who choose to undergo weight loss surgery are generally patients suffering from moderate to severe obesity, and as we all know, obesity can cause a variety of complications, one of which is sleep apnea syndrome. Suffering from this disease will make people in the sleep state repeated apnea and hypoventilation, hypercapnia and sleep disruption, which may lead to hypertension, coronary heart disease, cerebrovascular disease, etc., and serious may also appear sudden death at night. Patients undergoing bariatric surgery who suffer from this disease are at risk of respiratory distress, hypoxemia, carbon dioxide accumulation and many other risks, so they need to take countermeasures and treat accordingly to reduce the riskiness of the surgery before the operation. In addition to its impact on surgery, sleep apnea syndrome also increases the risk of anesthesia, especially in patients who also suffer from type 2 diabetes and cardiovascular diseases. In this case, the physician in charge of anesthesia should conduct a more detailed and thorough evaluation, and in addition to preparing for difficult intubation, should strengthen the respiratory cycle detection and airway maintenance during the operation. After the surgery is completed, this type of patient will also require more precautions. For example, the patient should be placed in a semi-recumbent or lateral position in the ward, avoiding supine lying. Low-flow oxygen should also be administered, and all parameters should be monitored. It is also because sleep apnea has a great impact on the operation, and some patients can’t even tell whether they have this problem or not, so the preoperative sleep and respiratory examination is particularly important. At the same time, in order to ensure that the operation goes smoothly, the preoperative examination is also necessary to inform the patient or his family, and fully communicate with them.