Alveolar lavage pathogenic microorganism metagenome host removal nucleic acid extraction method

The invention provides an alveolar lavage pathogenic microorganism metagenome host removal nucleic acid extraction method. The method comprises the following steps: S1, performing differential splitting decomposition to remove a host: sampling, centrifuging, discarding supernatant, resuspending in a PBS (Phosphate Buffer Solution), adding a saponin solution for incubation, and then adding sterile water for incubation again; adding NaCl, shaking uniformly, centrifuging, discarding supernatant, and suspending in the PBS solution again; S2, host DNA removal: adding a PMA solution into the solution obtained in S1, and carrying out dark incubation and illumination incubation; S3, microbial thallus wall breaking: carrying out wall breaking treatment on the solution obtained in S2 by adopting grinding beads and lysozyme; and S4, nucleic acid extraction: performing DNA extraction on the solution obtained in S3, and detecting the quality. According to the invention, an azido propyl bromide ingot (PMA) is used. When th