The invention relates to a biohazard assessment visualization method based on a Google map. The method comprises the following steps: 1) taking a Bernoulli curve function as a biohazard particle simulated aerosol diffusion model; 2) expressing the aerosol diffusion model as a polar coordinate form; 3) drawing an aerosol diffusion curve by using the GPolygon class of Google Maps API, and obtainingan actual hazard area corresponding to the aerosol diffusion curve by using getArea (); 4) dividing the actual hazard area into a plurality of areas, arbitrarily acquiring the longitude/latitude coordinates of a point in each area, then judging which county the area belongs to by a getLocations () function of Google Maps; 5) invoking the population density data of the county from a database of Google Maps, and multiplying the population density data by the area of the county so as to obtain the number of harmed people in the county; and 6) adding the numbers of harmed people in the divided areas so as to obtain a total number of harmed people. The method provided by the invention is high in accuracy and efficiency, and can be widely used in sudden biohazard assessment processes.