Biomass derived porous carbon materials have large specific surface area, good pore structure and excellent conductivity, but there are few surface active sites, which limits its application in electrochemical sensing. In order to improve its electrochemical activity, an N,P co-doped biomass pyrolytic carbon material was prepared using lotus root as biomass feedstock and ammonium polyphosphate (APP) as nitrogen and phosphorus dopant. The material was characterized in terms of structure, morphology and elemental composition using SEM, TGA, XRD, XPS and FTIP. Using this material as electrode modification material, an electrochemical sensor for detecting rutin was constructed. The electrochemical performance of the sensor and the electrochemical behavior of Ru on different electrodes were studied by EIS, CV and DPV. The results show that the modified electrode prepared by the material with the mass ratio of lotus root to APP of 1:1 and pyrolysis temperature of 800℃ has the best detection effect on RU. Under optimal conditions, the RU concentration has a linear relationship with the response current of the modified electrode, and the detection range is 0.01~10.0 μmol/L, the minimum detection limit is (1.19±0.04)×10-8 mol/L（S/N=3）。In addition, the modified electrode has a good effect on the determination of RU in Shuanghuanglian oral liquid and healthy human urine samples.