Endometriosis is a gynecologic condition, but before the use of laparoscopy, its preoperative diagnosis rate did not exceed 70% even for experienced gynecologists and only 20% for those with less experience. Endometriosis has two main symptoms, one is secondary progressive dysmenorrhea, decreased fertility or even infertility, and other secondary symptoms are irregular lower abdominal pain or painful intercourse, difficulty urinating, and painful defecation. For these patients, doctors often find painful nodules in the rectal septum and poorly defined adhesive masses in the pelvis during gynecological examination. Although patients with endometriosis often have typical symptoms and signs, there are many patients whose symptoms do not exactly parallel their condition, for example, those with large tumors do not necessarily have dysmenorrhea, and those with heavy dysmenorrhea do not necessarily have extensive ectopic endometrial implants. Adhesions and pressure pain due to endometriosis are often mistaken for pelvic tuberculosis and chronic pelvic inflammatory disease; endometriosis nodules in the rectal fossa of the uterus are sometimes not easily distinguished from nodules of ovarian cancer. Some active chocolate cysts are often confused with mature teratomas of the ovary, and cysts may be mistaken for subplasma fibroids when they are in close proximity to the uterus. The advent of laparoscopy, on the other hand, has made a quantum leap in the early diagnosis of ectopic disease. Through laparoscopy, gynecologists can systematically observe each pelvic organ and its plasma membrane surface, understand the extent of endometriosis, depth of infiltration, and degree of adhesions, and stage the disease based on these findings to determine the severity of the disease and guide treatment. The magnification of the lesion can be changed by changing the distance between the laparoscopic lens and the lesion. Therefore, the lens is placed close to the suspicious lesion during the examination, which can confirm the diagnosis of small early lesions. Early clinical cases without typical endometriosis history, signs and symptoms are mainly diagnosed and staged by laparoscopy, especially in the examination of patients with unexplained infertility. The now common American Fertility Society’s staging of endometriosis is based on laparoscopy. In patients with chronic pelvic pain who are suspected of having endometriosis, laparoscopy can be performed to determine whether the condition is endometriosis, chronic pelvic inflammatory disease, or pelvic stasis. In addition, in cases where chocolate cysts are suspected but not completely certain, laparoscopic puncture can be performed to analyze the nature of the cyst fluid and to obtain tissue from the cyst wall for pathological examination to clarify the diagnosis. In patients with infertility, a tubal patency test can also be performed at the same time. A harmless dye is injected through the cervical opening and the tubal patency is directly observed under the laparoscope. The lesion is then treated according to the laparoscopic findings, and further treatment options are selected according to the characteristics and stage of the lesion and the urgency of fertility requirements. Laparoscopy has been increasingly used in the diagnosis and treatment of endometriosis due to the advantages of less damage and faster postoperative recovery. For small or multiple ectopic foci, various methods such as laser, electrocoagulation and microwave can be used for cauterization under laparoscopy. For large chocolate cysts, cyst removal is feasible, preserving normal ovarian tissue; semi-radical or radical surgery such as ovarian or even hysterectomy is feasible for a few patients with severe and recurrent endometriosis without fertility requirements to avoid recurrence. At present, laparoscopy and surgery have become routine diagnostic and therapeutic tools for patients with endometriosis in most hospitals.