Whether it is easy to deliver with a large fetal head is determined by the size of the pregnant woman’s pelvis. If the pregnant woman has a large pelvis, wide pelvic outlet, high pubic symphysis and shallow pelvis, even if the fetal head is relatively large, the fetal head will be deformed during the progress of labor after the fetal head is in the pelvis. As long as the fetal position is occipital-anterior, the fetal head is better connected with the pelvis, and it is easier to deliver smoothly. The factors that determine whether the labor progresses smoothly are labor force, birth canal, fetus and the mental state of the pregnant woman. Therefore, the large biparietal diameter of the fetal head is not the only factor that determines labor, but needs to be evaluated by a professional obstetrician in the late pregnancy.