The invention discloses a glyphosate water-soluble tablet and a preparation method thereof and belongs to the technical field of pesticides. The glyphosate water-soluble tablet is characterized by comprising, by weight, 10% to 80% of glyphosate acids and/or glyphosate salts, 5% to 40% of disintegrating agents, 5% to 20% of surface active agents, 0% to 60% of fillers and 0% to 5% of adhesion agents. Compared with various novel glyphosate granules in a current market, the glyphosate water-soluble tablet has the advantages that the processing is simple, the moisture content is extremely low, the energy consumption of a drying process is reduced, the equipment investment is small, drifted dusts in processes of processing and packaging the glyphosate granules are reduced by the aid of one-time forming of the glyphosate water-soluble tablet, the problem of difficult absorption of tail gases and dusts is solved, the screening process is omitted, the reworking rate is reduced, the environment-friendly safety is improved, the glyphosate water-soluble tablet belongs to a novel glyphosate preparation, and simultaneously the packaging, transporting and storing costs are greatly lowered.