Difficult labor includes abnormalities in labor force, birth canal, fetus and psychosocial factors, after one or more of these four factors occur, they will interact with each other to cause difficult labor, as follows: 1, abnormal labor force: abnormal labor force includes weak uterine contractions, or excessive uterine contractions; 2, abnormal birth canal: generally includes abnormalities in the bony birth canal and soft birth canal. Bone birth canal abnormalities, the most common is the pelvic stenosis, including the entrance plane in the pelvis and exit plane stenosis; 3, fetal anomalies: including previa abnormalities, fetal orientation abnormalities, and then fetal size abnormalities, such as the often said occipital transverse position, occipital posterior position or breech position, fetus too large or double or multiple fetuses; 4, psychosocial factors: many people will have a fear of labor pain during labor, in the process of delivery will Anxiety, depression, excessive mental tension, these can cause, uterine contraction weakness, and finally lead to obstructed labor.