The invention relates to a polyaspartate coating material for cars. The coating material consists of a main agent and a curing agent, wherein the weight part ratio of the main agent to the curing agent is (100: 20) to (100: 50). According to the preparation method, polyaspartate resin is matched with materials, such as pigments of various colors, an anti-settling agent, a dispersing agent, filler, a defoamer, a leveling agent, a sagging prevention assistant and the like, and then is matched with isocyanate, a catalyst, a diluent and the like, so as to prepare a series of polyaspartate coating materials for cars. The series of coating materials for cars can be coated on the surfaces of the car heads and car bodies of various cars under the condition of natural drying or low-temperature baking, and the thickness of a once-coated film is 20-80 microns. According to the coating material, the drying time is adjustable, sagging can not occur when a coating is too thick, and the sprayed coating film is level, has excellent physical and chemical properties and plays an excellent role in protecting and decorating the cars. The coating material can be widely applied to the coating of products, such as car bodies, car compartments, car parts and the like.