TECHNOLOGY FOCUS - ENVIRONMENT - Preferred Components: The amount of sludge aggregate is 10-60 wt.%. The sludge aggregate is sludge or sludge and fermentation waste slag, agricultural bio-waste or humus. The sludge is mud sludge, primary sludge of sewage treatment plant, excess activated sludge or anaerobic digestion sludge. The fermentation waste slag is citric acid slag, distillers' solubles, Penicillium mycelium waste, bean slag, cephalosporin slag or sauce residue. The agricultural bio-waste is tofu skin, sugarcane slag, corncob powder, waste starch, plant straw or plant straw waste.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The plastic film further comprises (in wt.%) plasticizer (0-30), supporting material (0-10) including fibrous material and/or inorganic fillers, waterproofing agent (0-10). The plasticizer is alcohol plasticizer, citric acid esters plasticizer, epoxy plasticizer, urea plasticizer, sodium bis-(2-ethylhexyl) sulfosuccinate. The fiber material comprises natural fiber and/or chemical fiber. The inorganic filling is coarse whiting powder, talc, kaolin or wollastonite powder. The waterproofing agent is siloxane fluorinated polyacrylate emulsion, silicone acrylic emulsion, silica sol or polyurethane. In the step (b), the adhesive agent comprises high polymer adhesive agent or other adhesive agent, whose amount accounts for 5-50 wt.% the amount of the sludge aggregate, where the high polymer adhesive agent is polyvinyl acetate, polyethylene glycol, polyvinyl alcohol, polylactic acid, polybutylene succinate, poly-3-hydroxybutyric acid, polyhydroxyalkanoate or polyurethane. The other adhesive agent is chitosan, starch, siloxane fluorinated polyacrylate emulsion, gelatin, hydroxyethylcellulose or sodium alginate. Preferred Method: In the step (b), the stirring and mixing reaction is carried out at 30-220 degrees C for 10 minutes to 10 hours at a stirring speed of 50-250 revolutions/minute. In the step (c), film-forming process is carried out to prepare the film using the film-forming mixture slurry, where the film forming process comprises blow-molding, pulp molding, flow delay molding, melt extrusion or extension molding, spraying method for spraying on the film or using film supporting material as a frame film. The method further comprises performing waterproof processing using waterproofing agent on the film, where the waterproof processing comprises soaking method or spraying method.