The invention discloses a method for on-line measuring charge-to-mass ratio of particles in a fluidized bed. The method comprises the steps of acquiring induction electrostatic current signals generated during a granule fluidization process through an annular induction electrode and pressure pulsation and differential pressure signals on two sides of the annular induction electrode, and obtaining the charge-to-mass ratio through the quantitative correlations between the electrostatic current and differential pressure signals. The detection result is accurate, and the detection apparatus is simple in structure, low in cost and wide in application scope. The method is applicable to real-time on-line detection of charge-mass ratio of particles in the fluidized bed.