The cycle of magnetic induction intensity was examined by smartphone installed Phyphox software and its magneto-mechanical sensor，which is the micro vibrational period of homogeneous arc．The magnetic ball

is fixed at the center of homogeneous arc．Then the measured data was imported into Origin software and the frequency of it versus time was plotted． Based on it，the micro vibration cycle of homogeneous arc was

calculated．The obtained values are consistent with the theoretical ones with relative error of 0．11%．This method is extended to study micro vibration of complex systems by a smartphone．