The invention discloses a method for unloading aluminum oxide from a prebaking aluminum electrolysis cell. According to the method, the crust breaking and the unloading of the prebaking aluminum electrolysis cell are simultaneously carried out, aluminum oxide is intermittently remained at least twice in a discharging pipe after entering into an unloading pipe from a fixed container, the intermittent remaining efficiency is accordant with the crust breaking frequency, and the crust breaking is carried out before each time of remaining of aluminum oxide. Aluminum oxide is subjected to segmentation remaining in the unloading pipe and is preheated by virtue of the high temperature of the aluminum electrolysis cell, so that the situation that aluminum oxide newly added into the electrolysis cell is agglomerated with electrolyte into blocks is effectively avoided, the dissolution and dispersion of aluminum oxide are accelerated, precipitates are unlikely to form at the bottom of a furnace, and the efficient and steady working of the electrolysis cell is promoted.