Abstract: The nano-sized powder materials are common samples in the field of chemistry and chemical industry. In the scanning electron microscopy (SEM) characterization of the nano-sized power materials, the following problems are usually emerged, such as low secondary electron yields, powder agglomeration resulting in the inability to observe nanomorphology, charging effects and so on. Silica spheres powder, ZSM-5 zeolite nanosheets and polystyrene spheres powder were used as the SEM samples. The SEM samples on substrates were unsprayed with a metal film, and were prepared by direct-coating the powder onto the conductive tap or silver paint and by drop-coating the dispersing solution onto different substrates, respectively. The effect of two preparation methods on SEM imaging, direct-coating and drop-coating of dispersing solution on a substrate, were compared. The results showed that the dispersing solution of the samples can effectively reduce the agglomeration of the powders, in which the drop-coating on the silicon wafer substrate could reduce the charging effect and background effect, and the nanoscale morphology of the powder can be clearly observed.