Epinephrine (Ep) is an important neurotransmitter, which plays an important role in the nervous system and glycogen metabolism of living organisms. Hence, a novel NCQDs/FeCoFe-PBA composite with FeCoFe-Prussian blue analogues (PBA) as the core and nitrogen-doped carbon quantum dots (NCQDs) as the shell was constructed by a one-pot hydrothermal method, and it was used for the efficient detection of Ep. As a good electroactive material, NCQDs in the composite not only improved the weak conductivity of FeCoFe-PBA, but also limited the self-aggregation of FeCoFe-PBA, and formed a uniform shell on FeCoFe-PBA. The heterogeneous structure formed between the core and shell layer resulting in NCQDs/FeCoFe-PBA nanocomposites with more active sites, electron transport channels and a larger effective surface area. Further, under optimal conditions, the electrochemical method was used to evaluate the NCQDs/FeCoFe-PBA sensor, and the results revealed that the sensor had exceptional sensing performance for Ep, with an excellent linear range from 0.01 to 306.7 μM and a low detection limit of 0.002 μM. Simultaneously, the practicality, repeatability, and stability tests yielded positive results, confirming the feasibility of practical development and application of NCQDs/FeCoFe-PBA.