The invention relates to a water-based varnish with good resolubility and high water scrubbing resistance and a preparation method therefor. The water-based varnish comprises the following ingredients, by weight, 30-50 parts of water-based acrylic emulsion, 5-30 parts of water-based alkali-soluble type acrylic resins, 10-20 parts of deionized water, 10-30 parts of ethanol, 0.5-8 parts of neutralizers, 5-15 parts of hydrophobic agents, 1-5 parts of water-based wax slurry, and 0.1-0.4 part of auxiliary agents. During preparation, part of deionized water is taken and mixed with water-based alkali-soluble type acrylic resins and neutralizers, the mixture is heated up to the temperature of 60-70 DEG C, and an acrylic ester aqueous solution is obtained; the acrylic ester aqueous solution, water-based acrylic emulsion, ethanol, hydrophobic agents, water-based wax slurry and the rest of deionized water are put into a reactor, and stirred uniformly at a low speed; then auxiliary agents are added, the above mixture is stirred at a high speed, and a water-based varnish is obtained. The water-based varnish has good resolubility during coating usage, does not block plates, can achieve high water scrubbing resistance after film forming, and well solves the problem of contradiction of resolubility and water scrubbing resistance after film forming of a varnish.