The fastest way to replenish amniotic fluid in late pregnancy is to actively look for the causes of low amniotic fluid and eliminate the causes, and the fastest way to replenish amniotic fluid is to inject saline into the amniotic cavity, but this method is rarely used in clinical practice. Pregnant women need to replenish amniotic fluid in late pregnancy, first need to actively find the causes of low amniotic fluid in late pregnancy, eliminate the causes to improve the amniotic fluid is the most effective way. The fastest way to replenish amniotic fluid is to inject saline into the amniotic cavity, but this method is invasive and less commonly used in clinical practice, and more often than not, pregnant women increase amniotic fluid by drinking water. If necessary, intravenous fluids can also be considered to replenish amniotic fluid. During late pregnancy, pregnant women need to closely observe the changes in amniotic fluid. If amniotic fluid is low, she needs to actively replenish it under the guidance of a specialist, so as to avoid intrauterine oxygen deprivation due to the lack of amniotic fluid, which may affect the growth and development of the fetus. In addition, if amniotic fluid rupture occurs in late pregnancy, pregnant women must go to the regular hospital to receive timely examination and treatment to avoid affecting the health of the fetus.