The kit is suitable for extracting high purity total DNA from fresh or frozen animal tissues, cells, blood, bacteria and other samples. This product can be purified to obtain a DNA fragment with a molecular weight of up to 50 kb. The purification process does not require the use of toxic solvents such as phenol or chloroform, and ethanol precipitation is not required. The kit uses an optimized buffer system to efficiently and specifically bind the DNA in the lysate to a silica-based centrifugal adsorption column. The inhibitors of PCR and other enzymatic reactions can be effectively removed by a two-step washing step, and finally a low-salt buffer is used. High purity DNA can be obtained by eluting with liquid or water. Purified DNA can be directly used in downstream experiments such as digestion, PCR, Real-Time PCR, library construction, Southern hybridization and so on.