The invention discloses a water self-adhesive spliced toy material and a preparation method thereof, and the water self-adhesive spliced toy material comprises the following components in parts by weight: 10-80 parts of prefabricated polyvinyl alcohol particles, 20-90 parts of a filling agent, 0 to 1 part of a lubricant and 0 to 6.0 parts of a pigment. The water self-adhesive spliced toy materialeasy in injection molding can be formed by using the prefabricated polyvinyl alcohol particles, adding the filling material with a proper proportion and supplementing the lubricant. The water self-adhesive spliced toy material is simple in preparation process, convenient to operate and control, stable in quality, high in production efficiency, low in manufacturing cost and capable of realizing large-scale industrial production. The water self-adhesive spliced toy material is capable of forming a movable combination body only by coating a connecting surface with water. Spliced blocks of any shapes can be manufactured through injection molding, and the manufactured spliced blocks are high in strength and high in hardness, has high temperature resistance and small deformation, can be splicedinto various planes and three-dimensional shapes, and the shape and the size of spliced toys are not limited by space.