The invention relates to a building method of an aluminum electrolysis cell, which comprises a conventional building method and comprises the following building steps: (1) when cathode blocks of the electrolysis cell are manufactured, symmetrically chamfering the upper end part of each cathode block along the longitudinal direction, and forming a transverse groove at the top of each cathode block; (2) when the cathode blocks are built, reserving a gap of 20-40mm between every two adjacent cathode blocks, and tamping the gap by cathode tamping paste, wherein the opposite chamfers of the adjacent cathode blocks and the cathode tamping paste filled into the gap form a trapezoidal groove, and the depth of the trapezoidal groove is the same as the depth of the transverse groove at the top of each cathode block; and (3) forming one or two longitudinal grooves at the bottom of each cathode block, laying steel bars of corresponding sizes in each longitudinal groove, and tamping the gap between each cathode block and each steel bar by cathode steel bar paste. The aluminum electrolysis cell built by the method can greatly reduce the horizontal current in aluminum liquid to enable the current density of the cathode blocks and the cathode steel bars to be more uniform, thereby greatly prolonging the service life of the electrolysis cell.