The invention discloses a current conversing method and device of aluminium electrolyser, which is characterized by the following: adopting transition conversing pattern to open or close groove; crimping short-circuit block on the column and column when the electrolyser lies at groove-closing time; making most of current enter into short-circuit mother wire circuit through power inlet end; entering current from short-circuit block into next electrolyser; realizing groove-closing; paralleling fuser on two ends of short-circuit hole when the electrolyser lies at groove-opening time; starting short-circuit block; connecting strong current on the fuser; breaking short-circuit block; fusing the fuser; making current of short-circuit into electrolyser; eliminating electric arc in the closed circuit.