The invention relates to a method for preparing rare-earth complex-containing mango preservative material master-batches. According to the method, LLDPE serving as carrier resin is added with tourmaline powder, rare-earth complex, diatomaceous earth, oleamide and sodium stearate to prepare the master-batches by means of cladding dispersion, interface modification, material mixing, extruding and granulating. In the characteristics of the rare-earth complex, the molar ratio of lanthanum ions to yttrium ions to samarium ions to cerium ions is (2.80-2.90):(0.55-0.60):(0.95-1.05):(1.25-1.35). The master-batches prepared by the method are added into LLDPE resin in a ratio of 7-10 percent and are subjected to blow-molding to prepare a film, the film is used for preserving and packaging mangos to inhibit breath strength and growth of surface microorganisms in the storing process, and the preservation period can be prolonged for 12-15 days at normal temperature.