Abstract: In this study, modified niobium acid was prepared by calcination method. The catalytic pyrolysis and pyrolysis product of kraft lignin were analyzed by Py-GC/MS at 650 ℃. The modified niobium acid (Nb-350) was characterized by FT-IR, BET, XPS and NH₃-TPD. The effects of catalyst-to-lignin weight ratio, pyrolysis temperature, pyrolysis time and heating rate on kraft lignin CFP were explored. FT-IR and XPS analysis showed that the crystallization water in the modified niobium acid decreased during the calcination process. BET analysis showed that the pore volume and mesoporous ratio of Nb-350 increased. NH₃-TPD showed that Nb-350 has weak acid sites. Pyrolysis products of kraft lignin mainly contained benzene, toluene, methyl phenol and methoxyphenols. Nb-350 promotes the yield of phenols (up to 85%). The pyrolysis parameters (pyrolysis temperature: 650 ℃, pyrolysis time: 40 s, catalyst-to-lignin ratio: 4) optimized to improve the yield of phenols and aromatic hydrocarbons.