Lignin, as the second abundant biomass after cellulose in nature, is a kind of renewable energy, and the depolymerization products of lignin can also be used as value-added products to improve economic benefits. The utilization of lignin has the dual value of environmental protection and economic benefit. However, due to the heterogeneity of lignin structure and the diversity of binding bonds, it is difficult to depolymerize, and the product is also uncertain, resulting in low utilization rate. At present, the commonly used lignin depolymerization methods are roughly divided into catalytic polymerization (pyrolysis catalysis, acid catalysis, base catalysis, etc.) and microbial depolymerization (Laccase, Manganese peroxidase, Lignin peroxidase, etc.), and the products produced by different depolymerization methods have certain differences. It is important to depolymerize lignin in different ways to obtain corresponding products. This review aims to summarize the common methods of lignin depolymerization, the depolymerization mechanism of different methods and the corresponding depolymerization products, so as to adopt suitable methods according to different needs, improve the utilization rate of lignin, and provide opportunities for the industrial application of lignin depolymerization in the future.