The invention relates to a method for synthesizing water glass-modified phenolic resin composite material by using a suspension method. The invention is characterized in that: the method comprises the following steps: 1) raw material selection: raw materials in weight proportions are as follows: water 20-250, phenol 90-160, formaldehyde solution 60-120, hexamethylenetetramine 15-35, Arabic gum powder 3-10, aluminum hydroxide powder 2-8 and water glass 1-150; 2) adding 0-60% the total weight of water, phenol and formaldehyde solution to a stirring reaction vessel, adding acidic solution until the pH value is in the range of 2-5; 3) adding a part of Arabic gum powder and hexamethylenetetramine in the reaction vessel, then adding water glass, uniformly blending rest of the homogenous mixture of the remaining Arabic gum powder and aluminum hydroxide powder and 50% of the rest water after the step 2), adding to the reaction vessel, dissolving the rest hexamethylenetetramine in the residual water, and adding the solution to the reaction vessel; and 4) washing, filtrating and drying to obtain the water glass-modified phenolic resin. The synthetic product has high molecular weight, good heat resistance and good high-temperature stability.