Causes of excessive amniotic fluid include pregnancy complications, twin pregnancies and maternal/fetal blood group incompatibility, which can be treated by controlling blood sugar, puncturing the uterus to release amniotic fluid and intrauterine blood transfusion. 1. Gestational comorbidities: excessive amniotic fluid caused by maternal diseases, such as diabetes mellitus, because hyperglycemia can cause fetal hyperosmolar diuresis, which can also cause excessive amniotic fluid. It is necessary to control the blood sugar of pregnant women to control the increase of amniotic fluid, mainly through diet and exercise to control. 2. Twin pregnancy: Twin pregnancy usually has monozygotic twin and dizygotic twin two cases, if there is a monozygotic twin, the two placenta’s arterial and venous anastomosis, it is very easy to trigger the twin transfusion syndrome, so that the recipient of the child’s circulating blood and urine volume increases, thus leading to excessive amniotic fluid. When the increase in amniotic fluid is obvious, the uterus can be punctured in the abdomen to release amniotic fluid. 3. Maternal and fetal blood group incompatibility: pregnant women and fetal blood group incompatibility, hemolysis can also cause excessive amniotic fluid, the patient can be treated with intrauterine blood transfusion. There are many causes of amniotic fluid, it is recommended that patients go to regular hospitals to find out the causes of amniotic fluid and then treat the symptoms to avoid serious consequences.