<p>The production of high-value nitrogen-containing compounds (NCCs) and nitrogen-doped biochar through biomass nitrogen-enriched pyrolysis is a promising approach for enhancing the economic potential of renewable resources. This study investigates the effect of pretreatment durations with <i>Phanerochaete chrysosporium</i> SHBCC D22643 on nitrogen-enriched pyrolysis of corn stover (CS) for producing nitrogen-containing bio-oil and nitrogen-doped biochar. The results show that fungal pretreatment duration significantly affects pyrolysis products. At 5 weeks pretreatment, the relative content of NCCs in bio-oil was significantly increased. The relative content of semioxamazide rose from 13.72% to 41.17%, which became the main component in the bio-oil. 2-Nitropropane peaks at 13.59% at 2 weeks pretreatment. For biochar, 5 weeks pretreatment achieves 9.55% nitrogen content and 21.93% graphitic-N on the surface. Based on the compositional characteristics of bio-oil, the pyrolysis mechanism of pretreated CS is also expounded.The study demonstrates that fungal pretreatment probably optimizes the oxalic acid-hydrazine condensation pathway by disrupting lignocellulosic structure and promoting urea penetration, providing a basis for directional regulation of NCCs and biochar nitrogen configuration in nitrogen-enriched pyrolysis.</p> Graphical abstract <p></p>