The invention discloses a multistage-heating difference frequency vibration fluidization system for oxidative infusibility of coal tar pitch spheres, which includes multiple stages of fluidized bed reactors and a temperature-controlling gas feeding apparatus, wherein the fluidized bed reactors are successively connected to each other in a stepwise distribution manner. Each fluidized bed reactor includes a shell, a porous distribution board, and a vibration exciter, wherein the shell is provided with a feeding inlet, a discharge outlet, an air inlet and an air outlet; the feeding inlet and thedischarge outlet are respectively disposed on two ends of the porous distribution board that is inclined from the feeding side to the discharge side; the discharge outlet of one fluidized bed reactoris connected to the feeding inlet of the next one fluidized bed reactor. The system significantly increases the oxidizing efficiency of the coal tar pitch spheres and reduces breaking ratio of coal tar pitch sphere granules.