The amorphous Fe78Si9B13 alloy was treated by low frequency pulse magnetic field (LFPMF) and nanocrystallized at a low temperature. The microstructures and the magnetic properties of the untreated and treated alloys were analyzed by M?ssbauer spectra and LDJ9600 vibrating sample magnetometer (VSM). The valence electron structures and the magnetic moment of the unnanocrystallized and nanocrystallized amorphous alloys were calculated using the method of Bond Length Difference (BLD) of the Empirical Electron Theory (EET) of solids and molecules. The error of the computed value in theory and experimental value of the magnetic moment is less than 7%, which satisfies the demand of first approximation, indicating that it can be realized that magnetic moment of amorphous alloy is calculated on the valence electron level.