This product is a new generation of water treatment agent, it has high efficient of chelation and dispersion effects, high value of calcium tolerance, and excellent antiscale dispersion effects. It can be used as antiscale corrosion inhibitor in circulating cool water system, especially suitable to circulating cool water system and oilfield refill water system in situations of high hardness, high alkali and high pH value. It has excellent antiscale property to calcium carbonate, calcium sulfate and calcium phosphate. In addition, it can efficiently inhibit the formation of silica scale, and stabilize such metal ions as Zn, Mn and Fe. PAPEMP can be used as antiscale corrosion inhibitor for prefilming antiscale agent in inverse osmosis system and in multistep flash vaporization system in which high salt concentration, high turbidity and high temperature are usually encountered (such as high temperature and high turbidity in coal vaporization system), accessory agent for weave, dyeing and papermaking (for example, yellow turnback inhibition agent), to replace EDTA, DTPA and NTA. The dosage of 5-100mg/L is preferred. Different from other water treatment agents, the more quantity is, the better the effect. PAPEMP can be built with polycarboxylic acids.