Deoxyribonucleic acid, also called DNA, is the main component of chromosome. Deoxyribonucleic acid carries the genetic information of synthetic RNA and protein, and guides the operation of biological development and life skills through semi-conservative replication. Deoxyribonucleic acid consists of deoxyribose, phosphoric acid and bases, including adenine, guanine and thymine. The structure of DNA is a double helix structure, and the binding is very stable. Deoxyribonucleic acid can store and transmit genetic information. Cells replicate genetic information through DNA and transmit genetic information through complementary nitrogenous bases sequences. In daily life, DNA can be used to identify criminals and criminal acts, fingerprint identification and paternity test, and forensic doctors can conduct forensic identification by separating DNA from blood, skin, saliva and other tissues and body fluids.