Polylactic acid (PLA), as a kind of biodegradable materials with excellent properties, is widely used in industry, packaging and pharmaceutical industries. With the widespread use of PLA, the amount of its production and consumption has increased dramatically, which will lead to a serious accumulation of PLA waste. Although PLA can be degraded under natural conditions, the degradation cycle is too long and the degradation products cannot be recycled directly. By chemical recycling methods, PLA materials can be depolymerized to generate corresponding small molecular products. After separation and purification, the products can be reused as monomers for the production of PLA or raw materials for synthesizing other chemical products, which can realize the recycling of resources. In this paper, the research status of the chemical degradation and recycling products of PLA materials in China and abroad in recent years was reviewed, and several main chemical depolymerization methods were introduced, including thermal cracking, hydrolysis, alcoholysis, enzymatic hydrolysis and photolysis. The advantages and disadvantages of each method were analyzed and summarized. Finally, the chemical degradation of PLA was prospected.