The invention discloses a high-efficiency oxygen-insulation water-insulation blended full-degradable plastic film. The high-efficiency oxygen-insulation water-insulation blended full-degradable plastic film is prepared from, by weight, 60 to 65 parts of corn starch, 7 to 9 parts of nano montmorillonite, 0.6 to 0.7 part of peanut oil, 1.2 to 1.4 parts of tetrabutyl titanate, 12 to 14 parts of ramie straw, 27 to 30 parts of polyvinyl alcohol, 1 to 2 parts of xanthan gum, 2 to 4 parts of sodium carboxymethylcellulose, 14 to 15 parts of polyethylene glycol, 7 to 9 parts of poly propylene carbonate, 4 to 6 parts of Pulullan, and 2 to 3 parts of ethyl silicon oil. According to a preparation method, synergistic effect of polyving akohol, polyethylene glycol, and poly propylene carbonate is realized; so that the melting point of polyving akohol is reduced, better blending with a starch master batch is realized, barrier property of plastic film is improved, and oxygen insulation and water insulation effects are excellent. The high-efficiency oxygen-insulation water-insulation blended full-degradable plastic film can be taken as food packaging bags and preservative film, and is capable of insulating oxygen and water, and realizing fresh-keeping effects; and prepared products are capable of satisfying using requirements and can be degraded rapidly after abandoning.