The invention discloses a monodisperse nano-silica production process by a chemical precipitation method. The chemical precipitation method is combined with high dispersion of a surfactant, tetraethoxysilane is used as a raw material for the first time on the basis of earlier literature, ammonia water is used as a catalyst, and monodisperse nano-silica particles are prepared by reasonably controlling reaction conditions. The monodisperse nano-silica production process has the advantages of simple experimental equipment, operation convenience, low surfactant consumption, good stability and the like, overcomes shortcomings that the size of particles is difficult to control and uneven in distribution, the particles are easy to agglomerate and the like in the traditional preparation method, and has industrial popularization and practical application values. In addition, nano-silica prepared in the process has high monodispersion, and the size of the nano-silica is uniform and controllable. Besides, interface bonding of the nano-silica and a polymer matrix is strengthened, carrying capacity of a polymer is improved, and accordingly the purpose of strengthening the toughening polymer is achieved.