Epinephrine is essential for maintaining the proper functioning of the heart, blood vessels, and central nervous system. Designing a cost-effective, efficient, and sensitive sensor for epinephrine with strong electrochemical performance is of great importance. Transition metal–carbon materials have garnered significant attention due to their low cost, wide availability, non-toxicity, and stable properties. In this work, we developed a novel nickel-doped nanoporous carbon (Ni-NC) sensor by modifying a zeolite imidazolate framework (ZIF-L) through chemical etching, structural transformation, and pyrolysis strategies, aimed at the sensitive detection of epinephrine. Compared to a two-dimensional (2D) structure, the three-dimensional (3D) structure offers a larger specific surface area and pore size, as well as more exposed active sites, thereby enhancing the catalytic performance of the Ni-NC sensor. The strong synergistic effect between the transition metal Ni and the carbon substrate enables Ni-NC to achieve rapid and efficient epinephrine detection. The sensor exhibits a linear range of 0.7–402.0 μM, a detection limit of 0.32 μM, and demonstrates excellent anti-interference, repeatability, reproducibility, and stability. Moreover, the sensor shows strong applicability in real sample analysis. This research presents a highly sensitive and efficient analytical strategy for the rapid detection of epinephrine.