Polyhydroxyalkanoates (PHA) is a biobased thermoplastic polyester synthesized through microbial fermentation from natural sugars or oils. It can be regarded as a “fully natural cycle plastic” - it replaces the carbon framework of petroleum-based plastics with the polyester chains naturally synthesized within microorganisms, thus being able to be completely degraded by microorganisms into water and carbon dioxide in almost all natural environments such as freshwater, seawater, and soil. PHA not only has similar heat sealing and barrier properties to traditional plastics, but also possesses excellent biocompatibility. Its degradation products can be metabolized by the human body and are widely used in environmentally friendly packaging, disposable tableware, agricultural mulch films, bone repair scaffolds, drug sustained-release carriers, and other high-end medical fields.