The invention provides a method for effectively enriching air medium microorganisms on the basis of a magnetic bead method. The method comprises the following steps: placing a filter membrane in a to-be-detected environment, performing the sampling in an adsorption manner, and placing the filter membrane after the sampling into an extraction container; adding an acid buffer solution with pH value of 2.0 to 2.5, then oscillating for 5 to 10 minutes, and then carrying out the ultrasonic dispersion for 10 to 20 minutes; adding ferroferric oxide magnetic beads into the extraction container, and continuously ultrasonically dispersing for 10 to 30 seconds; taking another separation container, charging the acid buffer solution into the separation container, pouring the ultrasonically-dispersed solution into the separation container, oscillating, uniformly mixing, standing for 1 to 10 minutes, and then separating magnetic beads to obtain separated magnetic beads. By adopting the technical solution, the air medium microorganisms with high enrichment amount, high concentration and convenience in detection can be obtained on the premise of low cost, so that the problem of difficulty in tracking, enriching and quantifying in the monitoring and analysis process of air medium microorganisms can be effectively solved.