The invention discloses a composite floor coated with a thermosetting polyurethane elastomer. The lower part of a floor surface layer is coated with an elastomer layer composed of the thermosetting polyurethane; the polyurethane elastomer layer is of long-acting viscosity, can be fitted with various ground bases better, and is excellent in sliding resistance and high-low temperature resistance; meanwhile, the composite floor can be reused without damaging the original ground bases. The composite floor is very convenient to pave; when partial composite floor is damaged, only the damaged part can be replaced, so that the floor decoration cost can be greatly reduced, and the composite floor is environment-friendly.