The invention relates to a cathode structure of an aluminium cell, in particular to an improved cathode structure of an electrolytic cell used for aluminium electrolysis. The improved cathode structure is characterized in that a converging groove is arranged on the cathode of the electrolytic cell along the length direction of the electrolytic cell, and an aluminium accumulation tank communicated with the converging groove is arranged at the end head in the length direction of the electrolytic cell. The cathode structure of the aluminium cell realizes the high-performance network type aluminium liquid flow guiding and collection through a flow guiding trench and a converging trench which are designed on the surface of the cathode; the aluminium accumulation tank is designed at the end head of the electrolytic cell for collecting and storing the aluminium liquid, so the polar distance can be shortened; the aluminium liquid generated during the electrolysis can flow in the aluminium accumulation tank through the flow guiding system at any moment, therefore, the thickness of the aluminium liquid layer can be effectively reduced and the heavy current of the electrolytic cell can be reduced or eliminated; and the polar distance and the cell voltage are conveniently reduced to the utmost extent due to the influence of the strong magnetic field to the aluminium liquid layer fluctuation and the current efficiency, and simultaneously, the purpose of higher current efficiency is achieved, therefore, the utilization ratio of energy is greatly improved and the electricity consumption is reduced.