Synthesized from isophorone diisocyanate (IPDI) and polyoxypropylene diol (PPG), Waterborne polyurethane (WPU) was prepared as a carbon source in the preparation of carbon dots (CDs) with hydrothermal method. Carbon dots (CDs) with different mass fractions were added to the reaction system of isophorone diisocyanate (IPDI) and polyadipate 1,4-butanediol diol (PBA) to prepare carbon dots/waterborne polyurethane composite materials. The structure and properties of the composite materials were characterized by fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), ultraviolet-visible absorption spectroscopy (UV), fluorescence spectroscopy and the mechanical properties tests. The results showed that the thermal stability, fluorescence performance and mechanical strength of the composite films were improved with the addition of carbon dots.When the mass fraction of carbon dots was 0.5%, the quantum yield and fluorescence lifetime of the composite film were 4.15% and 2.43 ns, respectively. The tensile strength and elongation at break of the films were 36.80MPa and 660%, respectively, which were 29.7% and 33.3% higher than those with no carbon dots added.