A fertilized egg that lays outside the body cavity of the uterus is called an ectopic pregnancy, formerly known as an ectopic pregnancy. The most common type of ectopic pregnancy is tubal pregnancy, which can account for about 95% of ectopic pregnancies. The possible causes of tubal pregnancy are: i. Inflammation of the fallopian tubes, which is the main cause of tubal pregnancy and can be divided into tubal mucositis and peri-fallopian tube inflammation. Secondly, when tubal pregnancy or surgery is performed, there is a history of tubal pregnancy, whether it is naturally absorbed after conservative treatment or undergoes conservative tubal surgery, the chance of recurrence of ectopic pregnancy in another pregnancy can reach about 10%. The incidence of tubal pregnancy in another pregnancy is 10%-20% with a history of tubal sterilization and surgery. Third, poor development or abnormal function of the fallopian tubes themselves, such as overly long fallopian tubes and poorly developed muscular layer, may also cause the occurrence of ectopic pregnancy. IV. Assisted reproductive technology in recent years has also increased the incidence of tubal pregnancy. V. Failure of contraception, such as failure of intrauterine device contraception and failure of oral emergency contraceptive pill contraception, has also increased the incidence of ectopic pregnancy.