Embodiments relate to a water soluble paint composition for a vehicle. The water soluble paint composition includes a core-shell microgel resin, a dimer-modified polyester resin, a (meth)acryl-modified polyurethane resin, a curing agent, a pigment, and water, wherein the dimer-modified polyester resin is included in an amount of 1 to 10 wt % with respect to 100 wt % of the water-soluble paint composition. When the water soluble paint composition according to various embodiments is used to paint a vehicle, air handling equipment and an oven are not needed, so that energy can be saved in the painting process, CO2 production can be reduced, costs can be saved for painting equipment and maintenance, and space for a painting line can be saved, and a paint layer can be formed having excellent smoothing, waterproofing, chipping resistance, and outer appearance.