Organic fertilizer capable of keeping soil fertility and preparation method of organic fertilizer

The invention discloses an organic fertilizer capable of keeping the soil fertility. The organic fertilizer is prepared from the following raw materials in parts by weight: 30-40 parts of rape seed cakes, 24-36 parts of rice husk, 8-12 parts of diatomite, 6-8 parts of turf, 5-8 parts of starch, 5-6 parts of slag, 4-5 parts of medical stone, 4-5 parts of EM microbicide, 3-5 parts of zeolite powder, 3-4 parts of ammonium hydrogen carbonate, 2-3 parts of amino acid, 2-4 parts of diammonium phosphate, 4-5 parts of potassium sulfate, 2-4 parts of chelated zinc, 3-4 parts of potassium dihydrogen phosphate and a proper amount of water. The organic fertilizer contains multiple nutrients, friendly to the environment and nontoxic and has the advantages of low cost and capability of improving the ecological structure of soil; under the circumstance that the EM microbicide is used for fermentation, organic materials are totally decomposed, so that organic matters and beneficial microorganisms of soil can be increased year by year and the soil fertility can be kept; the added medical stone is capable of stabilizing, improving and balancing the physical properties of the soil; the added turf has the capability of improving the water-retaining, ventilating and fertility-keeping properties of the soil and increasing nutrients.