This series of silica microspheres are non-porous spherical particles with large specific surface area; hydrophilic surface and good dispersibility. At the same time, because of their good optical and mechanical properties, they can meet the scientific research needs of the application field of inorganic particles. Silica microspheres are divided into two categories. The surface is unmodified and the surface is modified with functional groups such as carboxyl, amino and streptavidin, which can be widely used in nucleic acid separation, cell separation, immunoassay and other scientific research fields.