NOVELTY - Setting method of nitrilotriacetic acid (NTA) restoring waste compost heavy metal anti-seepage insulating layer comprises: (i) preparing experimental material by (i.a) taking annual Lolium perenne L. as an experimental material, domestic waste compost from Tianjin small starch compost factory, and test soil as surface layer soil, respectively drying the compost and soil, and sieving, and (i.b) taking an insulation material, isolating e.g. Bacillus subtilis from Tianjin small starch compost, preparing a leaching solution, and adjusting pH; and (ii) performing the test method.    USE - The method is useful for blocking heavy metal migration into the compost and seepage into the soil to reduce heavy metal content (claimed).    ADVANTAGE - The method: reduces the harmful substances and heavy metals from the waste compost and soil; induces the lawn plants under the synergistic effect of chemical chelating agents and microorganisms; increases the absorption time in the compost, and heavy metal enrichment; and reduces the migration of the heavy metals into the deep soil.    DETAILED DESCRIPTION - Setting method of nitrilotriacetic acid (NTA) restoring waste compost heavy metal anti-seepage insulating layer comprises: (i) preparing experimental material by (i.a) taking annual Lolium perenne L. as an experimental material, domestic waste compost from Tianjin small starch compost factory, and test soil as surface layer soil, respectively drying the compost and soil and sieving by using a 2 mm sieve for future use, and (i.b) taking an insulation material comprising from bottom to top (in g) zeolite (20), bone meal or crab shell powder (45) and sawdust (20), isolating Bacillus subtilis and Actinomycetes from Tianjin small starch compost treatment plant of domestic waste compost, preparing a leaching solution by using ammonium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium nitrate, magnesium nitrate and sulfuric acid, where the concentration of sulfate ions, nitrate ions, chloride ions, ammonium ions, magnesium ions, calcium ions, potassium ions and sodium ions is respectively 14.96, 6.54, 1.68, 3.71, 0.82, 1.38, 0.64 and 0.78, and adjusting pH to 5-6 using hydrochloric acid for the future use; and (ii) performing the test method by (ii.a) selecting lawn matrix compost, performing interlayer arrangement by selecting polyvinyl chloride (PVC) pipe (diameter 7.5 cm; length 25 cm), where the bottom of the pipe is fixed with a nylon mesh (diameter 0.2 mm) to support the pipe in the soil and compost, and lifting the pipe, where the lower part of the pipe is provided with a conical bottle connected with filtrate, (ii.b) filling 500 g of dry soil into the PVC pipe, paving, filling the insulation material (85 g), then introducing them into the compost (280 g), and paving in the layer, (ii.c) setting up microbial inoculum and lawn matrix layer system to establish sowing of Lolium perenne L. seeds (0.6 g) in the PVC pipe, irrigating with tap water, maintaining the whole field water to 60-65%, planting temperature and relative humidity to respectively 23-30 degrees C and 30-65%, and illumination intensity to 400-1000/ mu mol m-2 second-1, (ii.d) after 30 days of planting Lolium perenne L., applying NTA sodium salt solution (150 ml; 5-15 mmol/kg of compost) on the compost surface, mowing Lolium perenne L. after 10 days of growing, placing the cut lawn plant of Lolium perenne L. at 80 degrees C in an oven for drying to obtain constant weight, and recording the ground biomass, (ii.e) the next day after mowing, using artificial leaching solution (150 ml) equal to 34 mm of precipitation, leaching for the first time, then after 7 days, spraying the solution (total 600 ml) for 4 times ( each time 150 ml), respectively weighing and collecting in a conical flask, mixing them uniformly for future use; and (ii.f) using TAS-990 atomic absorption spectrophotometer to measure the content of heavy metals comprising cadmium, chromium, copper, lead and nickel in the digestive liquid. An INDEPENDENT CLAIM is also included for an application of the above-mentioned method in blocking heavy metal migration into the compost and seepage into the soil to reduce heavy metal content, comprising using NTA (15 mmol/kg-1) in combination with the insulating layer comprising (in g) zeolite (20), bone meal or crab shell powder (45) and sawdust (20).