The invention discloses degradable environmental-friendly plastic which comprises the following raw materials: polylactic resin, modified poly-beta-hydroxybutyric acid PHB, dinonyl phthalate DINP, pentaerythritol rosin ester, mung bean protein, oxidized cassava starch, alkali hargil, calcium carbonate, musa textilis fiber, linear low density polyethylene-graft-maleic anhydride, gamma-glycidoxy propyl trimethoxy silane, a methyl methacrylate-butadiene-styrol copolymer, aluminum potassium sulfate, citrate, an ethylene-vinyl acetate copolymer, ethylene bis-oleamide, diphenyl-methane-diisocyanate, an anti-mold antibacterial agent, a degradation agent, an antioxidant, a stabilizing agent, a flame retardant, a smoke inhibitor, a tackifier, a softening agent and an ultraviolet light absorber. The degradable environmental-friendly plastic disclosed by the invention is relatively good in tensile strength and elongation at break, good in impact resistance, relatively low in water absorption, good in light transparency, and free of damage to the environment as the plastic can be completely degraded into carbon dioxide and water after 136-141 days.