Abstract: Fluorescent carbon quantum dots as a novel nano mimic enzyme have been widely used in various fields in recent years due to their reliable reactivity, adjustable catalytic activity and good stability. This study aimed to provide a basis for the preparation of fluorescent carbon quantum dots and their application as mimic enzymes. Fluorescent carbon quantum dots were prepared by one-step hydrothermal method with corncob, sunflower seed shell and grape seed food waste as raw materials, and their characterization, peroxidase activity verification and enzymatic reaction kinetics were studied. Firstly, three kinds of fluorescent carbon dots were prepared by one-step hydrothermal method, their morphologies were observed by transmission electron microscope, their optical properties were determined by ultraviolet spectrum scanning and fluorescence spectrum scanning, and their functional groups were obtained by Fourier transform infrared spectrum scanning. The peroxidase activity and enzyme steady-state kinetics of the three kinds of fluorescent carbon dots were investigated with ABTS catalytic chromogenic reaction system as reference. The sizes and internal ultrastrucutres of the three fluorescent carbon quantum dots were determined by TEM. The images revealed that the three fluorescent carbon quantum dots had a prominent nanostructure and good divergence with no apparent aggregation. The illustrations showed the three fluorescent carbon quantum dots as spherical particles with a smooth surface and minimal particle size. It indicated that three fluorescent carbon quantum dot nanoparticles were successfully prepared. The ultraviolet spectrum scanning showed that all three fluorescent carbon quantum dots had a significant ultraviolet absorption peak around the absorbance of 325 nm. The FT-IR spectra showed that the surface of corncob fluorescent carbon dots and sunflower seed shell fluorescent carbon dots contained abundant hydroxyl groups, which ensured a good hydrophilicity and stability. The surface of grape seed fluorescent carbon dots contained hydrophilic groups, such as carboxyl groups. The fluorescence intensity of corncob fluorescent carbon dots was obviously higher than that of the other two fluorescent carbon dots. The results of three fluorescent carbon dots mimetic enzymes showed a specificity in peroxidase activity and had a good substrate affinity. Based on these results, the three kinds of carbon dots will have a broad application value in food industry, medical research and industrial production.