The invention discloses an X80 pipeline steel plate with thickness larger than or equal to 26.4 mm used in a longitudinal submerged arc welding pipe and a production method thereof. The X80 pipeline steel plate comprises the following components in percentage by weight: 0.035-0.055% of C, 0.15-0.30% of Si, 0.25-0.55% of Mn, less than or equal to 0.012% of P, less than or equal to 0.0012% of S, less than or equal to 0.006% of N, 0.065-0.085% of Nb, 0.010-0.025% of Ti, 0.15-0.30% of Cr, 0.02-0.05% of Al, 0.08-0.15% of Mo, 0.1-0.2% of Cu and 0.30-0.50% of Ni. The production method comprises the steps that casting blanks are stacked and slowly cooled for more than 24 h; and the casting blanks are heated, rough rolled, fine rolled, cooled, straightened, tempered, straightened again and then isair cooled to room temperature on a cooling bed. By adopting the production method, the anti-acid performance is good; the yield strength (horizontal) : Rt 0.5 is greater than or equal to 555 MPa; Rmis greater than or equal to 630 MPa; A50.8 is greater than or equal to 25%; a pipe wall is not cracked with increasing conveying pressure; the thickness is greater than or equal to 26.4 mm; structureuniformity is good; Rt0.5/Rm is less than or equal to 0.91; V-notch impact work KV2 is greater than or equal to 250 J at minus 20 DEG C; the drop weight tear tenacity DWTT:SA is greater than or equalto 85% at minus 15 DEG C; and the Vickers hardness HV10 is less than or equal to 250.