Abstract: The non destructive analysis method of Ni Mn Co catalyzer alloy by energy dispersive X ray fluorescence (EDXRF) is studied. A series of Ni Mn Co catalyzer alloy with known contents of Ni,Mn,Co are as standard samples, and the intensities of characteristic X ray of these standard samples are acquired by EDXRF spectrograph. A working curve is established by means of fitting the relation between the contents of Ni, Mn, Co and intensities of characteristic X ray from standard samples. When an unknown sample is determined, the contents of Ni, Mn, Co are obtained by filling the intensity of characteristic X ray of the sample measured by EDXRF spectrograph into the working curve. The measured range of content is 60 %～85 %,15 %～30 %,2 %～8 %, respectively for Ni, Mn and Co. The precision of this method is 0.5 %,2 %,5 %, respectively for Ni, Mn and Co.