This kit is designed for the extraction of nucleic acid (DNA/RNA) in human biological fluids such as nasopharyngeal swabs, sputum, broncho lavage fluid and alveolar lavage fluid. This kit provides all necessary reagents for highly pure viral nucleic acid (DNA/RNA) extraction from samples such as human nasopharyngeal swabs, sputum, broncho lavage fluid and alveolar lavage fluid. The extracted pure viral nucleic acid can be directly applied for Reverse Transcription, PCR, RT-qPCR, RT-PCR, Next Generation Sequencing, Biochip Analysis and other related assays. Based on the specially embedded silica-coated superparamagnetic beads, the nucleic acid rather than proteins or other substances are adsorbed by hydrogen bonds and static electricity in the unique buffer system. The magnetic beads with nucleic acid adsorbed are then washed to remove other free components like proteins and salt. And the magnetic beads would release nucleic acid after the addition of low-salt buffer, so as to obtain rapidly separated and purified nucleic acid. This kit enables a simple, fast, safe and efficient operation process to extract viral nucleic acid with a high yield, high purity, stable and reliable quality. It is also suitable for the automatic extraction at high-throughput workstations.