Pregnant women may experience lumbar discomfort during pregnancy, the following reasons can be considered: 1, the pregnant woman’s center of gravity shifts forward in late pregnancy, and the forward shift of the center of gravity causes the pregnant woman’s head, neck and shoulders to move backward and the waist to protrude forward, forming the typical posture of pregnant women. This typical posture causes the pregnant woman’s low back muscles to be under constant tension, so it is easy to cause low back discomfort; 2, the general pregnancy of pregnant women’s bone quality does not change, only special circumstances such as too many pregnancies, too close, and do not pay attention to the supplementation of calcium, vitamin D, may cause osteoporosis, can also be the cause of pregnancy, late pregnancy pregnant women’s low back discomfort; 3, pregnancy, late pregnancy pregnant women’s low back discomfort, which may be related to relaxin secreted by the placenta during pregnancy. The relaxation of the bone and joint ligaments caused by relaxin causes the symptoms of low back discomfort in pregnant women in late pregnancy. If the symptoms of low back discomfort in pregnant women are serious, it is recommended to consult a doctor promptly to clarify the cause and give local physiotherapy, hot compresses and medication if necessary.