Abstract: The migration and transformation behavior of nitrogenous compounds during municipal sludge pyrolysis is crucial for pollution control and resource recovery. Using a bibliometric approach, this study systematically analyzed the migration and transformation pathways, influencing factors, and control strategies of nitrogenous compounds during sludge pyrolysis. The results show that existing studies mainly focus on the transformation and control of nitrogenous compounds in the solid, liquid, and gas phases. In the solid phase, nitrogenous compounds are converted from reactive organic nitrogen to heterocyclic nitrogen and quaternary ammonium nitrogen. In the liquid phase, nitrogenous compounds evolve from amines and amides to nitrogen-rich heterocycles and nitriles. In the gas phase, nitrogenous compounds are mainly converted from proteins to NH₃ and HCN. Pyrolysis temperature, pyrolysis atmosphere, and heating rate are the main factors affecting nitrogen migration and transformation; these factors influence the migration and transformation pathways by changing the extent of cracking of nitrogenous compounds, the residence time of volatiles, and the radical environment. In addition, control can be achieved by adding metal oxides or biomass, which suppresses the release of NO_x precursors such as NH₃ and HCN. Overall, this study can provide a theoretical basis for directional control of nitrogen transformation pathways of nitrogenous compounds and for improvement of sludge resource recovery efficiency during municipal sludge pyrolysis.