The effect and mechanism of decolorization were studied with magnesium sulfate and amphoteric 2% polysilicate zinc on the brown granulated syrup under high pH conditions. The factors and levels of response surface analysis were determined on the basis of single factor tests. The decolorization process was optimized by response surface analysis to obtain the optimum process conditions: magnesium sulfate of 500 mg/L, dosage of 2% silica polysilicic acid zinc of 1.57%, and pH 11. Under this condition, the decolorization rate reached 92.21%. The composites and sugar juice system were characterized by scanning electron microscopy (SEM) and potential analyzer. The results showed that the decolonization mechanism was electric neutralization and adsorption.