This paper analyses the microstructure of different types of particles in PM10in Beijing-Tianjin-Tangshan urban agglomeration atmosphere in spring and summer by using field emission scanning electron microscopy (FESEM), in which the distribution characteristics of the size and number of the different types of particles in PM10are specifically analyzed by using image analysis software. The research result shows that the types of particles in Beijing-Tianjin-Tangshan urban agglomeration atmosphere are unknown particles, soot aggregates, mineral particles and spherical particles. According to the proportion of the three partials in the atmosphere, the three cities ranks as follows: in the aspect of unknown particles, Tianjin ranks first, which is followed by Tangshan and Beijing; in the aspect of soot aggregates, Tangshan ranks first ,which is followed by Beijing and Tianjin; in the aspect of mineral particles, Beijing ranks first ,which is followed by Tangshan and Tianjin; in the aspect of spherical particles, Beijing ranks first ,which is followed by Tangshan and Tianjin;