Abstract: With the development of nearly 20 years of assisted reproductive technology and the expanded period of infertility treatment, twin pregnacy and the number of older pregnant women are increasing year by year, resulting in heated discussions about prenatal twin pregnancy screening. Compared with single pregnancy, twin pregnancy meet more difficulties in terms of prenatal screening and diagnosis. For the last 30 years, as the serum markers of fetal, ultrasonic technology and non-invasive prenatal screening technology develop, remarkable changes have taken place in prenatal screening and prenatal diagnosis.