There are many clinical causes of perineal tears, including general delivery, assisted delivery, long-term constipation, trauma and coital factors, etc. 1. General delivery: during delivery, the fetal head is delivered, the vaginal opening and surrounding tissues are compressed and locally thinned, which may lead to perineal tears if care is not taken to protect the perineum, and may also cause anal damage in severe cases. Therefore, during the observation of labor, it is necessary to correctly estimate the size of the fetus, understand the fetal position and the situation of the previa site; 2. Assisted delivery: for women with posterior occipital position and exit stenosis, a large lateral incision must be made during forceps assisted delivery, and if necessary, a bilateral incision can be made, which may cause tearing if the perineum is not properly protected; 3. Long-term constipation: if the patient has been squatting and sitting for a long time and has been constipated for a long time, resulting in dry stool, the lower part of the rectum will The lower part of the rectum will absorb the water from the stool and form a fecal stone. Excessive force during defecation may lead to perineal laceration; 4, trauma; if the patient has a blow or a foreign object that damages the anus and other causative factors, it may also lead to perineal laceration, and the wound can be clearly observed through visual examination; 5, excessive force during intercourse: mainly due to the patient’s previous inflammation, as the vagina is prone to dryness and loss of elasticity, this situation may also lead to perineal injury.