Abstract: Reasonable and correct sample preparation is a critical prerequisite for high-quality scanning electron microscopy (SEM) characterization. The process of fixing the sample to the sample holder is a brief but essential step that is often underestimated. Improper sample preparation can lead to a variety of problems during characterization, such as charging effect, image drift, surface distribution ghosting and particle aggregation, which not only affect the characterization effect and increase the difficulty of testing, but also may miss important informations. The key points of sample preparation were summarized, including the selection of conductive adhesive and sample holder, methods of sample fixation, establishment of electron migration channel, and coating techniques, and the principles and reasons were expounded, hoping to help the users of SEM improve the characterization effect by optimizing sample preparation techniques.