The head-first position is the best for delivery, and the occipito-anterior position is the best for head-first delivery. The left occipital anterior position is where the fetus’ head faces down toward the mother and the face faces the right side of the mother (the fetus’ occipital bone is on the left side of the mother); the right occipital anterior position is where the fetus’ head faces down toward the mother and the face faces the left side of the mother (the fetus’ occipital bone is on the right side of the mother), both of which are normal fetal positions. In addition, the decision of whether the fetus can be delivered vaginally depends on four conditions, namely labor force, birth canal, fetal size and maternal psychological factors. Labor force is the contraction force of the uterus. Strong contractions and long duration can promote the progress of labor and facilitate natural delivery. The birth canal includes the bony birth canal and soft birth canal, both of which are free from deformity and obvious narrowing and can enable the fetal head to pass smoothly. The size of the fetus is also a factor that should not be ignored. If the fetus is over 4kg, it is necessary to be alert to the difficulty of natural delivery and the possibility of obstructed shoulder delivery. The mental state and psychology of pregnant women are very important for natural childbirth. Fear and anxiety will affect contractions and increase the difficulty of natural childbirth.