Agricultural ammonium polyphosphate capable of being chelated with medium trace elements and preparation method of agricultural ammonium polyphosphate

The invention discloses agricultural ammonium polyphosphate capable of being chelated with medium trace elements. The agricultural ammonium polyphosphate is characterized by comprising the following components in parts by weight: 10000 parts of agricultural ammonium polyphosphate, 200-2000 parts of a trace element additive, 1-100 parts of a sulfur-containing agent, 1-50 parts of a precipitation inhibitor, 1-50 parts of an emulsifying agent, 1-20 parts of an acid and alkali regulating agent, 1-5 parts of an oxidant and 1-5 parts of an amino acid type nutrient. A water-soluble agricultural ammonium polyphosphate fertilizer is compounded so that ammonium polyphosphate and the additive which are originally incapable of being chelated with metal ions or are low in chelation quantity have the chelating capability; the prepared chelated type ammonium polyphosphate is moderate in acid-base property; the solution is stable and free of precipitates within three months; the suitable application temperature range is from -15 DEG C to 40 DEG C; the agricultural ammonium polyphosphate is convenient to popularize and use nationwide.