Reburning pyrolysis gas from biomass (i.e., biogas) for NO reduction was investigated experimentally. All experiments were performed on a bench-scale test facility. Both the flue gas and the biogas used in the experiments were simulated gases. In the experiments, the influences of individual components of biogas, reburning temperature, residence time, SO2 Concentration, initial NO concentration, moisture, and equivalence ratio on the NO reduction efficiency were studied. Experimental results show that biogas reburning can effectively reduce NO in simulated flue gas and that the components of biogas affect the NO reduction efficiency greatly. In particular, cyclopropane plays an important role. Among all those considered, the temperature and the residence time are favorable factors, while the SO concentration and the initial NO concentration are adverse parameters. Increasing the equivalence ratio benefits NO reduction initially and reaches a maximum value at about 1.15, after which the impact on NO reduction is reversed. The effect of moisture on the NO reduction is quite weak.