The doped SnO2 carbon nanofiber (SnO2-CNF) composites were prepared by electrospinning technology. Morphology of the composites prepared by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectrometer (EDS), x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. We used electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) to demonstrate the electrochemical performance of SnO2-CNF composites. In addition, we constructed an electrochemical sensor using the composite nanomaterials we prepared to achieve simultaneous detection of Acetaminophen (APAP) and p-Hydroxyacetophenone (p-HAP). The linear range of APAP is 0.50-700 mu M, the detection limit is 0.086 mu M; the linear range of p-HAP is 0.20-50 mu M, and the detection limit is 0.033 mu M. It has also been successfully applied to the detection of actual samples and serum environments, and satisfactory recovery rates have also been obtained.