At present, traditional storage technologies mainly use silicon-based materials as storage media, but the existing silicon resources in the world cannot meet the growing data storage needs of data. With the development of the data era, innovation in storage technology has faced challenges. DNA molecules store rich genetic information, and from the perspective of chemical biology, DNA molecules can be used as a medium for data information storage. This provides a new opportunity for storage technology. Unnatural base nucleotides can expand the genetic alphabet and increase the storage capacity, but there are still many issues to be resolved in their practical applications. This article reviews the progress of DNA storage technology, analysing the current state of DNA storage, unresolved technical challenges, and development prospects. Furthermore, it introduces unnatural base pairs (UBPs) as a new direction in synthetic biology, highlighting their potential advantages and technical challenges in the field of DNA information storage.