The invention discloses a method for detecting chloramphenicol residual in a functional food through HPLC-MS-MS. The method comprises the following steps: weighing a sample, adding deuterated chloramphenicol as an internal standard solution, adding ethyl acetate, ammonium hydroxide and anhydrous sodium sulfate, homogeneously extracting, centrifuging, and transferring the obtained supernatant to a heart-shaped bottle; concentrating the supernatant in the heart-shaped bottle to dryness; dissolving with water, carrying out ultrasonic treatment, adding n-hexane, carrying out vortex mixing, allowing the obtained solution to stand for layering, discarding n-hexane which is the upper layer, adding n-hexane, carrying out vortex mixing, allowing the obtained solution to stand for layering, transferring the obtained water phase to a centrifuge tube, centrifuging, and allowing the centrifuged water phase to go through a filter membrane to obtain a final solution for the determination through HPLC-MS-MS; accurately weighing a chloramphenicol standard substance, carrying out ultrasonic dissolving with chromatographically pure methanol, adding the chromatographically pure methanol to a constant volume, and preparing chloramphenicol standard substance solutions having different concentrations; determining the chloramphenicol standard substance solutions through the HPLC-MS-MS to obtain a standard curve; and calculating according to obtained examination data through the standard curve to obtain the concentration of chloramphenicol in the sample to be measured. The method has the advantages of good accuracy, high precision and good linearity.