Biodegradable polymer foamed bead capable of being formed by steam compression molding

The invention discloses biodegradable polymer foamed beads capable of being formed through steam compression molding. The biodegradable polymer foamed beads are prepared from, by weight, 10-88 parts of PBS, 10-88 parts of PLA, 1-4 parts of chain extender master batch, 1-3 parts of nucleating agent master batch and 5-12 parts of supercritical CO2 foaming agent. Wherein the concentration of the optical isomeric D-lactic acid monomer in the PLA molecular chain is 2-8%; pBS and PLA are used as polymer matrixes, a chain extender and a nucleating agent are added, the chain extender and reactive end groups of PLA and PBS are subjected to chain extension and branching reactions, the nucleating agent can improve the cell nucleation rate and reduce the cell size, and the biodegradable polymer foamed beads are continuously and efficiently prepared; in addition, the foamed beads are good in heat resistance and can be subjected to steam compression molding, and steam compression molding products with good bonding among th