Abstract: In this paper the porous magnesium silicate was prepared by hydrothermal synthesis method and template method with magnesium chloride and silica gel as precursors. The magnesium silicate was characterized by XRD,FTIR and SEM analysis. Porous magnesium silicate was used as adsorbent and adsorption as an index,the effects of adsorption time and initial concentration on the adsorption of gallic acid by porous magnesium silicate were investigated. The characterization results showed the mesoporous spherical porous magnesium silicates with a pore diameter of 5 nm and 22 nm was obtained. The adsorption results showed that the pseudo-second-order equation provided the best correlation to the experimental data(R² was 0.9965、0.9941、0.9941)when the initial gallic acid concentration were 25,50,75 mg/L,and the adsorption isotherm could be described by Freundlich isothermal adsorption equation(R²=0.9926). The method can provide a theoretical research basis for the adsorption and decolorization of sugar industry.