Polylactic acid resin

The invention provides a polylactic acid resin. The polylactic acid resin is prepared through melt blending of a first lactic acid polymer, a second lactic acid polymer and a chain extender; the first lactic acid polymer is a first aliphatic-aromatic copolyester-polylactic acid block copolymer; the second lactic acid polymer is at least one of polylactic acid and a second aliphatic-aromatic copolyester-polylactic acid block copolymer; and the chain extender has a specific structure. The polylactic acid resin provided by the invention includes an aliphatic-aromatic copolyester chain segment, so the flexibility of the polylactic acid resin is enhanced. The polylactic acid resin has a high melting point. Experiment results show that the elongation at break of the polylactic acid resin is high and reaches 510%, and the melting point of the polylactic acid resin is 200DEG C or above.