The invention discloses a cathode flat steel plate 08Al2 for an electrolytic cell, and a production method thereof. The flat steel plate 08Al2 comprises the chemical compositions of, by mass, 0.07-0.10% of C, no more than 0.02% of Si, no more than 0.25% of Mn, 1.5-2.2% of Al, and the balance Fe and inevitable impurity elements. The production method comprises the processes of smelting, heating, rolling, cooling and heat treatment. According to the cathode flat steel plate 08Al2 for the electrolytic cell, and the production method thereof, through the reasonable compositions and production process design, the thickness of the obtained flat steel plate 08Al2 is 100-130 mm, the texture is ferrite and pearlite, the yield strength Rp0.2 of the steel plate is greater than and equal to 345 MPa, the tensile strength Rm is greater than and equal to 500 MPa, A50 is greater than and equal to 33%, the hardness HB is less than and equal to 131, the tensile property Rp0.2 at the high temperature of600 DEG C is greater than and equal to 185 MPa, meanwhile certain fire resistance is achieved, and the requirements of electrolysis of aluminum oxide through a 800 KA current can be met.