The invention relates to a method for recycling N-(Phosphonomethyl)iminodiaceticacid (PMIDA) in PMIDA production wastewater, an application and a special device. The method comprises the following steps: 1, regulating the weight content of the PMIDA in the PMIDA production wastewater, and then adding hydrogen peroxide to remove formaldehyde; 2, adding the processed wastewater into a neutralization kettle, regulating the pH value, adding the wastewater into a triple effect evaporation system, enabling the wastewater processed in the triple effect evaporation to enter into an evaporation kettle, and evaporating acid water so as to enter into a biochemical treatment system; 3, enabling primary mother liquor to enter into the evaporation kettle, adding hydrochloric acid to regulate the pH value, carrying out negative-pressure evaporation concentration, and carrying out solid-liquid separation, wherein the solid is industrial salt, and the liquid is PMIDA solution. The PMIDA solution prepared by the invention has the PMIDA content of about 13%, not only can resolve the problem of recycling the PMIDA, but also can treat the PMIDA and phosphorous acid in the wastewater, thereby reducing the phosphorus content of the wastewater and enabling wastewater discharge to accord with the national standard.