As a promising alternative to traditional plastics, the widespread application of biodegradable plastic (BP) will help solve worsening environmental problems. Enzymes such as cutinase, lipase, protease and esterase produced by bacteria and fungi in the environment play a crucial role in the degradation, recycling and valorization of BP by degrading them into low-molecular-weight oligomers or small monomers. These enzymes offering advantages such as high efficiency, cleanliness, safety and environmental friendliness, making them more competitive in environmental restoration and circular economy. This review describes in detail the occurrence and distribution of enzymes involved in the degradation of BPs (represented by PHB, PLA and PCL). Omics methods (metagenomic and proteomic) combined with high-throughput platforms can screen out BP-degrading enzymes in different environments, and then use protein engineering to optimize the degrading enzymes to improve enzymatic degradation efficiency. Finally, we focus on the methods and strategies for the commercialization of degrading enzymes, future research prospects and challenges are also discussed. This review highlights the importance of BP-degrading enzymes in the bio-cycling of BP, and expected to drive the widespread use of BP.