Abstract: Curcumin (Cur) is an important food pigment, and its daily intake is strictly limited. Therefore, it is of great significance to develop a simple, rapid and sensitive method for the analysis of Cur in food. In this study, hydrophobic carbon dots (HB-CDs) were prepared by one-step hydrothermal reaction using flaxseed oil as a single carbon source. A new method for fluorescence sensing of Cur based on fluorescence resonance energy transfer (FRET) mechanism was developed with HB-CDs as energy donors and Cur as energy acceptors. The prepared HB-CDs were spherical with an average particle size of 3.3 nm, mainly containing C and O elements. The optimal excitation and emission wavelengths of HB-CDs were 350 nm and 425 nm, respectively. When Cur was added to the HB-CDs solution, with the increase of Cur concentration, the fluorescence intensity of HB-CDs (425 nm) decreased significantly, while the fluorescence intensity of Cur (525 nm) increased gradually. After the interaction between HB-CDs and Cur, the fluorescence lifetime of HB-CDs was significantly reduced, indicating that the interaction mechanism between HB-CDs and Cur was fluorescence resonance energy transfer (FRET). Quantitative analysis of Cur can be achieved by the fluorescence changes of HB-CDs. Under the optimal experimental conditions, the detection limit of the method was 20 nmol/L, and the linear range was 0.2-200 μmol/L. In addition, the method has been successfully applied to the determination of Cur in candy, milk powder and condiment samples, and the recoveries were 83.3%-112.0%. The prepared fluorescence analysis method can be used as an effective method for the detection of Cur in food samples.