Silicon is one of the most abundant elements in the earth’s crust， and also a beneficial element for plants. It has the effect of promoting plant growth and improving crop yield. Numerous studies have shown that silicon plays an important role in enhancing plant stress resistance as well. This article systematically reviewed the research progress of silicon enhancing plant resistance to biotic stress （including pathogens， pests， etc.） and abiotic stress （drought， salt damage， heavy metals， etc.） to further study the relevant mechanisms of silicon enhancing plant stress resistance. Studies existed have comprehensively shown that silicon can stabilize cell structure and improve plant morphology to enhance plant physical defense， and strengthen chemical defense by balancing nutrient absorption and regulating hormone metabolism. At the same time， it participates in gene expression regulation and improves plant molecular defense. And the future direction of studying silicon was prospected，such as the coupling mechanism of silicon resistance to various stresses， the in-depth study on the biochemical and molecular mechanisms of silicon improving plant stress resistance， and the development of new silicon fertilizers and supporting fertilizationtechnology.