The work aims to study the plasticizing effect of two environment-friendly modifiers of propylene carbonate (PC) and polypropylene carbonate glycol (PPC) on polylactic acid (PLA) and the thermal shrinkage, crystallinity and oxygen permeability of PLA/PC and PLA/PPC heat shrinkable films during tensile recovery. PC and PPC were blended with PLA by twin screw extruder. Differential scanning calorimeter (DSC), Fourier transform attenuated total reflection infrared spectroscopy (ATR-FTIR), X-ray diffractometer (XRD), electronic universal testing machine and differential pressure gas permeability instrument were used to study the modification effect of PC and PPC on PLA and the thermal shrinkage, crystallinity and oxygen permeability of PLA/PC and PLA/PPC heat shrinkable films during tensile recovery. The tensile strength of the heat shrinkable film modified by PC decreased to 16.8 MPa, the elongation at break increased to 26.6%, the oxygen transmission rate (To) could reach 1 020.4 cm3/(m2.d.Pa), and the recovery rate (Rr) was only 27.5%. The tensile strength of the heat shrinkable film modified by PPC decreased to 23.6 MPa, the elongation at break increased to 12.5%, and the Rr of PLA/PPC heat shrinkable film could reach 83.3%. After stretching, the To was only 915.8 cm3/(m2.d.Pa), showing good oxygen resistance. The flexibility of PLA/PC heat shrinkable film has been improved, but stress relaxation is prone to weaken the recovery stress of molecular chains, resulting in poor heat shrinkable properties, reduced difficulty in oxygen penetration, and increased To. PLA/PPC heat shrinkable film has good flexibility. After stretching, the crystallinity increases, the molecular chain can be well oriented, and the heat shrinkable property is good. The regularity of molecular chain increases, oxygen penetration difficulty increases, To decreases and oxygen resistance improves.