In order to explore the effects of different siliceous materials on the phase of calcium silicate hydrate synthesized by hydrothermal method, the effects of temperature and silicon-to-calcium ratio on the product were studied. The phase of calcium silicate hydrate was analyzed by X-ray diffraction (XRD), and the reaction efficiency of different siliceous raw materials with Ca(OH)2 was investigated. The results show that the reaction efficiency of different siliceous raw materials with Ca(OH)2 from high to low is diatomite, quartz and perlite. In the diatomite-lime system, the amorphous silicon dioxide Si—O in diatomite is easier to be destroyed, and it has instability, resulting in higher reaction efficiency of diatomite. In the quartz-lime system, with the increase of silicon-to-calcium ratio, CO2 in the air can participate in the reaction to generate tilleyite and scawtite, while tobermorite and xonotlite gradually disappear. The reaction product can be effectively controlled by reasonably adjusting the silicon-to-calcium ratio and hydrothermal temperature. This is of great significance to the selection of different siliceous raw materials, the control of products of calcium silicate hydrate and the application field of calcium silicate hydrate synthesized by hydrothermal method.