The kit is used to extract pathogenic microorganism genomic DNA/RNA from serum, plasma,cultured cells, saliva, alveolar lavage fluid, nasopharyngeal aspirate and swab samples. The kit uses a magnetic bead and buffer system with a unique isolation function. The surface of the magnetic bead is modified with special chemical groups, which have extremely strong enrichment ability for DNA/RNA under certain conditions and can reversibly release DNA/RNA when the conditions are changed to rapidly separate and purify DNA/RNA and to remove impurities like proteins as far as possible. The DNA/ RNA extracted by this kit can be widely used for various downstream molecular biological experiments, including enzyme digestion,fluorescent quantitative PCR, library construction, Southern blotting, chip detection, high throughput sequencing and other experiments.