A waterborne automobile
coating composition is provided. The composition is prepared from, by weight, 20-60 parts of a waterborne
polyurethane dispersoid, 1.0-3.5 parts of a dispersing agent, 5-15 parts of
titanium dioxide, 5-15 parts of precipitated
barium sulfate, 0.1-0.5 part of
carbon black, 0.5-1.5 parts of a
defoamer, 3-8 parts of a waterborne hydroxy
acrylic acid dispersoid, 0.1-0.5 part of an organic amine, 6-12 parts of amino resin, 0.1-1 part of a substrate
wetting agent, 1-3 parts of an explosion-proof auxiliary agent, 1-5 parts of a cosolvent, 20-40 parts of deionized water and 0.1-1 part of a
thickening agent. The waterborne
polyurethane dispersoid is a compound of a
polycarbonate-type waterborne
polyurethane dispersoid having hydroxy groups and a
polyester-type waterborne polyurethane dispersoid preferably. The
coating composition has excellent resistance to rock
crash, and can meet requirements on an automobile
coating process including three times of coating and one time of baking, namely a 3C1B process, in the field of environment protection.