The technology that silicic acid was pressurized under high temperature in order to dehydrate and transform was investigated in the paper.The effects,such as the ratio of liquid to solid,pressure,temperature,and reaction time on the dehydration rate and volume shrinkage rate,were researched.The experimental results show that the dehydration rate of silicic acid is up to 41.20%,accompanying with the volume shrinkage rate of 40.37%after silicic acid is pressurized under high temperature in the high-pressure kettle.The results of silicic acid tested by SEM indicate that the metasilicate acid molecules and water molecules are closely arranged,and there are almost no gaps before pressure reaction.There are many gaps accompanying with formatting lamellar structure after pressure reaction.The experimental results indicate the effect that silicic acid is dehydrated and transformation is obvious under high temperature and pressure. The technology that silicic acid was pressurized under high temperature in order to dehydrate and transform was investigated in the paper. The effects, such as the ratio of liquid to solid, pressure, temperature, and reaction time on the dehydration rate and volume shrinkage rate, were researched. The experimental results show that the dehydration rate of silicic acid is up to 41.20%, accompanying with the volume shrinkage rate of 40.37% after silicic acid is pressurized under high temperature in the high-pressure kettle. The results of silicic acid tested by SEM indicate that the metasilicate acid molecules and water molecules are closely arranged, and there are almost no gaps before pressure reaction. There are many gaps accompanying accompanying formatting lamellar structure after pressure reaction. the experimental results indicate the effect that silicic acid is dehydrated and transformation is obvious under high temperature and pressure.