Abstract：In order to ensure more accurate detection of ammonium phosphate in dry fire extinguishing powders, through a large number of experiments, the influencing factors on the content test results of ammonium dehydrogenate phosphate in fire extinguishing powders and control measures were discussed. The effects of different experimental conditions and operation method on the test results were focused on.The results show that adding amount of acetone as 2 mL, the sample is dissolved in water at 70 ℃, adding precipitant at boiling state, C6H18O24P6 concentration reaches 40 mL, the test results not only can guarantee the accuracy of data, but also satisfy the standard requirements.

Keywords：fire extinguishing powders; ammonium dihydrogen phosphate; test