The incidence of subcutaneous emphysema in laparoscopic pneumoperitoneum is 2.7%, and large subcutaneous emphysema with abnormally elevated PETCO2 is not uncommon. Therefore, subcutaneous emphysema caused by laparoscopic surgery should be taken seriously by anesthesiologists! Prevention of subcutaneous emphysema: ①Remind the surgeon: do not set too high pneumoperitoneum pressure in excessive pursuit of an open intraoperative view; also operate with caution to avoid repeated penetration of the abdominal cavity with the pneumoperitoneum needle, and keep the abdominal wall incision small and do not leave a redundant gap. ② Close monitoring: the anesthesiologist should check whether pneumoperitoneum forms in the skin around the frontal area and neck, and pay close attention to whether there is any abnormal elevation of PETCO2.