The invention relates to a water-soluble alkyd resin used for a toy lacquer, which comprises the following components in portion by weight: 180 to 200 portions of tall oil acid, 60 to 70 portions of trimellitic anhydride, 80 to 100 portions of diglycol, 50 to 60 portions of pentaerythritol, 30 to 40 portions of trimethylolpropane diallyl ether, 60 to 70 portions of dimethylolpropionic acid, 1 to 2 portions of hypophosphorous acid, 8 to 10 portions of ammonia water, and 500 to 520 portions of deionized water. The invention also discloses a water-soluble alcohol acid toy lacquer prepared by using the water-soluble alkyd resin as a principle component, and the synthesized water-soluble alkyd resin can be dried into a film without adding a drier; besides, because the formulation of the toy lacquer prepared by using the water-soluble alkyd resin as the principle component adopts water-soluble components, the toy lacquer achieves zero VOC, contains no heavy metal ions, and meets the requirements on the environmental protection performance of the resin.