TIANSeq DNA Fragmentation Module is a kit designed for the construction of high-throughput sequencing platform library, which is used for fragmentation of large fragment DNA before library construction. The module adopts the principle of time-dependent enzymatic reaction to randomly cut double-stranded DNA into 200~500 bp fragments according to different reaction time. The obtained fragments are blunt-ended double-stranded DNA fragments, the 5' end group contains 5'-P, and the 3' end group contains 3'-OH, so that subsequent dA-tailing or adapter ligation can be directly performed. Random fragmentation of double-stranded DNA by TIANSeq DNA Fragmentation Module shows that the product has no base preference, and the sequencing coverage rate of different types of fragmented DNA is consistent with that of mechanical shearing.