A method for synthesizing a pre-hydrolyzed polysilicate, wherein a polysilicate is applied as a reactant when synthesizing the pre-hydrolyzed polysilicate, and the total amount of water added in the reaction system is specified. The method is capable of omitting a condensation reaction by applying a polysilicate as a reactant, thereby significantly shortening synthesis time and reducing production costs when compared with a typical synthesis method in which alkoxysilane-based monomer compound is used as a reactant. In addition, the gelation reaction time and the weight average molecular weight can be easily controlled, and a pre-hydrolyzed polysilicate excellent in storage stability and processability can be synthesized.