Diethylenetriamine pentamethylene phosphonate sodium is an organophosphorus series scale inhibitor. Its molecular formula is C9H28O15N3P5, and its relative molecular weight is 573.2. Diethylenetriamine pentamethylene phosphonate sodium is non-toxic, miscible with water, has better scale inhibition and corrosion inhibition effect, and has good temperature resistance, which can inhibit the formation of carbonate, sulfate and phosphate scale. Especially when the pH value is 10-11, calcium carbonate still has a good scale inhibition performance, and the scale inhibition effect at this time is 2 to 3 times higher than that of hydroxy-ethylenediphosphonic acid and amino trimethylenephosphonic acid. Another outstanding feature is that the combination with manganese ions has a good corrosion inhibition ability on carbon steel and copper alloys.