The accurate identification of the genetic mechanism of siliceous rocks (SiO2) has always been a challenging issue in geological research. As the direct tracer isotope of siliceous rocks, silicon (Si) isotope holds great potential in revealing the genetic mechanism of siliceous rocks. In recent years, with the rapid development of high-precision Si isotope testing and analysis techniques, significant progress has been made in tracing the silicon sources, migration processes, and sedimentation-diagenesis evolution backgrounds of different siliceous rocks using Si isotope. To further promote the broader application of Si isotope in constraining the genetic mechanism of siliceous rocks, this paper reviews the genetic types of siliceous rocks, the analytical testing methods of Si isotope, the fractionation mechanisms, and its applications in the study of siliceous rock genesis, and reaches the following understandings: Siliceous rocks can be classified into hydrothermal genesis, volcanic genesis, biogenic genesis, and metasomatic genesis based on their genetic types. Both multi-receiver inductively coupled plasma mass spectrometry and secondary ion mass spectrometry have high precision in Si isotope testing, reaching accuracies of better than ±0.10‰ and ±0.10‰ - ±0.22‰, respectively. The fractionation mechanism of Si isotope involves multiple aspects. Diffusion causes the selective migration of Si isotopes and influences the degree of isotopic fractionation. Factors such as temperature, pressure, and chemical composition interact during the crystallization process, determining the degree of Si isotope fractionation. Evaporation affects the fractionation of Si isotopes by altering the chemical composition and physical properties of the melt. In low-temperature geological processes, Si isotope fractionation is more significant than in high-temperature geological processes, such as chemical weathering, biogenic-abiotic precipitation, biological absorption, and adsorption. Organisms absorb silicon during the process, causing isotopic fractionation and resulting in changes in the relative abundance of silicon isotopes in biogeochemical processes. There are differences in Si isotope fractionation among different organisms during the absorption process. The application of Si isotope in the study of siliceous rock genesis demonstrates its unique advantages, such as revealing the hydrothermal activity characteristics of hydrothermal siliceous rocks, the magmatic origin and evolution of volcanic siliceous rocks, the formation mechanism of biogenic siliceous rocks, and the silicon sources of metasomatic siliceous rocks. To more accurately identify the genetic mechanism of siliceous rocks, future research needs to conduct in-depth explorations in improving the analytical testing precision of Si isotope, accumulating large sample data, clarifying the fractionation mechanism, and constructing genetic theoretical models. This paper showcases the unique advantages and significance of Si isotope in the study of siliceous rock genesis, providing a useful reference for future research directions and application fields.