Abstract: Silicon in plants is the fourth essential element, which plays an important role in the quality, safety and yield of crops. However, the promotion and application of silicon fertilizer are not ideal at present. The study of diatomite-based silicon fertilizer will redefine the current pattern of silicon fertilizer. First, the mechanism of diatomite-based silicon fertilizer is comprehensively discussed in terms of improving drought resistance, disease resistance, insect resistance, lodging resistance, salt resistance, frost resistance, heavy metal resistance, and increasing plant yield and quality. Then, the difference, classification and application status between diatomite-based silicon fertilizer and traditional silicon fertilizer are expounded from the application aspect, and the role of diatomite-based silicon fertilizer and the problems existing in its research and application are analyzed. The purpose is to provide a reference for the research and development of diatomite-based silicon fertilizer, and discuss that diatomite-based silicon fertilizer has excellent characteristics that other silicon fertilizers do not have, which is of great significance to the research of silicon fertilizer and diatomite-based silicon fertilizer.