The invention provides an aqueous pressure-sensitive adhesive, which comprises the following components in percentage by weight: 54-81% of rubber latex, 5-10% of acrylic resin emulsion, 10-30% of tackifying resin emulsion and 4-6% of anti-aging agent emulsion, wherein the weight percentages of the various components are dry basis weights of the components. The invention further provides a preparation method of the aqueous pressure-sensitive adhesive. When being applied to surface protective paper, the aqueous pressure-sensitive adhesive provided by the invention is capable of protecting surfaces of products, such as acrylic plates, polycarbonate plastic plates, polystyrene plates, polyvinyl chloride plates, glass, marble and wood furniture decorative plates, under the ultra-low peeling strength, and avoiding the conditions, such as foaming, edge warping, and residual after tearing.