Carbon quantum dots with good biocompatibility can be used as nanomaterial carriers to improve the bioavailability of curcumin. In this paper, green tea was used as raw material to provide a green synthesis method for preparing carbon dots nanoparticles, and Curcumin was loaded to prepare carbon quantum dots/Curcumin nanocomposites (CQDs/Cur). A series of characterization methods were used to study the morphology and chemical structure of composite nanoparticles. The tea carbon dots had the characteristics of excitation wavelength dependence, salt solution stability and light stability. Finally, the antioxidant activities of CQDs/Cur nanocomposites were investigated by DPPH, ABTS^•+, hydroxyl radical, metal ion chelating and reducing power assays. The compound system not only improved the antioxidant performance of curcumin, but also retained the antibacterial activity of curcumin. These results suggested that tea carbon quantum dots loaded with curcumin had the potential to be developed as natural antioxidants and antibacterial agents.