The invention relates to X70 station yard steel with excellent toughness and large wall thickness and a production method thereof, which belong to the technical field of low-carbon structural steel production. A plate blank comprises the following chemical compositions: 0.03-0.09 percent of C, 0.01-0.30 percent of Si, 1.40-1.85 percent of Mn, not more than 0.015 percent of P, not more than 0.004 percent of S, 0.01-0.06 percent of Alt, not more than 0.008 percent of N, not more than 0.0002 percent of H, 0.008-0.02 percent of Ti, 0.03-0.10 percent of Nb, 0.01-0.30 percent of Mo, one or more of 0.00-0.30 percent of Cu, 0.00-0.30 percent of Ni and 0.00-0.30 percent of Cr, and balance of Fe and inevitable impurity elements. The heating temperature of the plate blank is 1140-1240 DEG C; first-stage controlled rolling is finished in an austenitic recrystallization zone, the reduction per pass is 10-30 percent, and the final rolling temperature is 1000-1080 DEG C; second-stage controlled rolling is finished in an austenitic non-recrystallization zone, and the final rolling temperature is 770-830 DEG C; and the plate blank is cooled to the temperature of 440-580 DEG C at the speed of 10-30 DEG C per second. The steel plate has the advantages of higher strength and excellent low-temperature toughness.