This kit provides the enzyme premix system and reaction buffer required for DNA library preparation, including all components except adapters and PCR primers for Illumina NGS platform. Compared with the conventional library preparation method, the kit is simple and convenient, and greatly reduces the library preparation time. In addition, this kit uses high f idelity DNA polymerase for library enrichment and unbiased PCR amplification, which expands the coverage area of the sequence and can effectively prepare DNA libraries for Illumina NGS platform. All reagents provided in the kit have undergone strict quality control and functional verification to ensure maximum stability in library preparation.