Heavy metal pollutants in atmospheric aerosols can adversely affect ecosystem and even human body. Therefore, it is necessary to detect and analyze the heavy metal pollutants in aerosols. Using laser-induced breakdown spectroscopy (LIBS), qualitative analysis of metallic elements and quantitative analysis of toxic heavy metals in atmospheric aerosol collected in 20 minutes were carried out, and LIBS analysis spectrum of Cr in aerosols under this experimental system was mainly studied. Then the relationship between the intensity of Cr in atmospheric aerosols and the contents of PM2.5 and PM10 published by China Environmental Monitoring Station was studied by normalization. Moreover, by establishing the calibration curve of heavy metal elements, the content of heavy metal elements in the aerosol samples was detected, and the corresponding detection limit was calculated. The experimental results show that atmospheric aerosols contain metal elements such as Cr, Na, Mg, Al, Ca, Fe, and Ba, and the intensity of the Cr element line is positively correlated with the PM2.5 and PM10 data published by China National Environmental Monitoring Centre, especially with the PM2.5 data. The correlation coefficient R2 of the calibration curve for heavy metal elements established in this experiment ranges from 0.995 to 0.997, and the detection limit ranges from 1.9 to 3.6 mg/kg, which indicates that the method can be applied for rapid detection of the content of heavy metal elements in atmospheric aerosol.