Non-invasive DNA prenatal testing has no obvious harm to the fetus or the pregnant woman. Non-invasive DNA prenatal testing technology only needs to take the pregnant woman’s venous blood, and use the new generation of DNA sequencing technology to sequence the free DNA fragments in the mother’s peripheral blood plasma, including the free DNA of the fetus, and analyze the results of the sequencing of the biological information, from which the genetic information of the fetus can be obtained, so as to detect whether the fetus suffers from the three major chromosomal disorders, which is the technology that is the most widely used at present.