Abstract: In this experiment, Fe porphyrin (PAF-40-Fe) modified electrode was prepared, and the electrochemical signal of morphine was detected at 0.2−0.8 V by differential pulse voltammetry. The results show that the electrode has good electrical conductivity during the detection of morphine. Under the optimal conditions, the linear relationship between the peak current and the concentration of morphine is good in the range of 1.5−1500 μmol/L, R² = 0.9945, and the detection limit is 0.5 μmol/L. The recovery of this method is 88.9%−105.3%. This method has good selectivity, simple sample preparation and fast detection, and has a good application prospect.