The invention relates to the technical field of environment-friendly materials, and discloses an environment-friendly
plastic bag which is of a three-layer
composite structure composed of the following raw materials in parts by weight: an outer layer, 60-80 parts of
polylactic acid, 40-60 parts of poly (
adipic acid) or butylene terephthalate with a thickness ratio of 40%, and a middle layer, 75-90 parts of modified cassava
starch, 25-35 parts of
polyvinyl alcohol and 3-8 parts of a citrate cross-linking agent with a thickness ratio of 30%. The inner layer comprises 80-95 parts of
polyhydroxybutyrate valerate and 15-25 parts of surface treatment
calcium carbonate, the thickness ratio of the inner layer is 30%, the three
layers are integrally formed through a co-
extrusion film blowing process, and a micron-sized groove array is arranged on the surface of the outer layer. The outer layer adopts the blend of
polylactic acid and
dibutyl phthalate, the
brittleness of
polylactic acid is made up by utilizing the flexibility of
dibutyl phthalate, and meanwhile, the use amount of pure polylactic acid is reduced, so that the cost is reduced by 40% compared with that of a pure polylactic acid bag; and 15 wt% of
stearic acid is added into the inner layer
polyhydroxybutyrate valerate to treat
calcium carbonate, so that the performance is ensured, and the cost is controlled at the same time.