Lignin is a complex three-dimensional amorphous natural aromatic polymer with great potential to be converted into biofuels as an alternative to traditional fossil fuels. Pyrolysis technology has been proven to be as an effective pathway for converting lignin into high-value chemicals. However, there are challenges such as low product selectivity and poor product stability in the direct pyrolysis process, which limit the efficient conversion and economic viability of lignin-based conversion. Currently, catalytic fast pyrolysis technology is regarded as a useful technology in overcoming these challenges. This paper extensively elaborates on the intricate structure of lignin by introducing its basic structural units and the multitude of linkage patterns it encompasses. Furthermore, it reviews the primary sources and diverse classifications of lignin. Subsequently, based on the pyrolysis characteristics of lignin, the key stages of its pyrolysis process, including the initial, primary, and carbonization stages, are extensively discussed. Due to the unsatisfactory quality of the direct pyrolysis products, this paper also explores the necessity of catalytic fast pyrolysis and provides a comprehensive introduction and overview of commonly used catalysts. Finally, the paper proposes the future development directions of lignin catalytic fast pyrolysis in terms of depolymerization and value addition.