Abstract: Plant fibers, composed of carbohydrates, phenolic substances, and terpenes, take the form of fibrous or fluffy strands, exhibiting a wide range of varieties and abundant resources. These fibers possess the advantages of high specific strength, biodegradability, and renewability, making them a sustainable source of natural green biomass. Utilizing plant fibers as reinforcement materials in resin-based composites not only facilitates the efficient and valuable use of plant fiber resources, thus enhancing the comprehensive application performance of composites, but also contributes to cost reduction in composite manufacturing. In recent years, research into various types of plant fiber-reinforced biodegradable composites has attracted considerable attention. This paper reviews the latest advancements in plant fiber reinforcement in three biodegradable polymer matrices: Polylactic acid (PLA), poly(butylene adipate-co-terephthalate) (PBAT), and poly(butylene succinate) (PBS). It provides an analysis and comparison of the overall performance of these different composites, offering insights into their application potential and forecasting future trends.