Late pregnancy can lie down to sleep, but should not lie down for too long, may cause supine hypotension syndrome, should try to take the left side of the sleeping position. Pregnant women in late pregnancy can adopt the sleeping position of lying down, as long as the pregnant woman feels comfortable, there is no problem, but the sleeping position of lying down should not be continued for too long, which may cause supine hypotension syndrome. The enlarged uterus in late pregnancy may compress the inferior vena cava, resulting in the restriction of reflux in the lower limbs and uterus, which affects the blood transportation of the placenta and fetus, leading to its poor blood circulation. It is recommended that women in late pregnancy adopt the left lateral lying position, which is conducive to increasing the blood flow to the placenta and improving the oxygen supply to the fetus in the uterus. It is important to master the correct sleeping position in late pregnancy and pay close attention to the changes of fetal movement.