The accurate identification of the genetic mechanism of siliceous rocks (SiO2) has always been a challenging issue in geological research. This paper aims to promote the broader application of silicon (Si) isotope in constraining the genetic mechanism of siliceous rocks by reviewing their genetic types, analytical testing methods, fractionation mechanisms, and applications in studying siliceous rock genesis.Methods: High- precision Si isotope testing techniques, including multi- receiver inductively coupled plasma mass spectrometry (MC- ICP- MS) and secondary ion mass spectrometry (SIMS), were analyzed for their accuracy and applicability. The fractionation mechanisms of Si isotopes were explored, encompassing diffusion, crystallization (influenced by temperature, pressure, and chemical composition), evaporation, and low- temperature geological processes (e.g., chemical weathering, biogenic—abiotic precipitation, biological absorption, and adsorption). Differences in Si isotope fractionation among organisms during silicon absorption were also investigated.Results: Siliceous rocks were classified into four genetic types: hydrothermal, volcanic, biogenic, and metasomatic.MC- ICP- MS and SIMS achieved high- precision Si isotope testing, with accuracies of better than ±0. 10‰ and ±0. 10‰~±0. 22‰, respectively. Key factors influencing Si isotope fractionation include diffusion, crystallization conditions (temperature, pressure, melt composition), evaporation, and low- temperature processes. Biological absorption induces significant isotopic fractionation, with variations observed among different organisms.Si isotopes demonstrated unique advantages in tracing hydrothermal activity characteristics, magmatic origins of volcanic siliceous rocks, biogenic formation mechanisms, and silicon sources of metasomatic siliceous rocks.Conclusions: Silicon isotopes exhibit significant potential in deciphering the genetic mechanisms of siliceous rocks. Future research should focus on improving analytical precision, accumulating large- scale sample datasets, clarifying fractionation mechanisms, and constructing theoretical genetic models. This review highlights the unique advantages of Si isotopes in siliceous rock studies and provides a foundational reference for future research directions and applications.