The invention discloses super-thick X70 pipeline steel and a manufacturing method thereof, wherein the pipeline steel is 30-32mm thick, and the pipeline steel comprises the following chemical ingredients in percentage by mass: 0.03-0.06% of C, 0.1-0.30% of Si, 1.30-1.60% of Mn, less than or equal to 0.010% of P, less than or equal to 0.0050% of S, 0.030-0.050% of Nb, 0.008-0.020% of Ti, 0.10-0.30% of Ni, 0.l0-0.30% of Cr, 0.10-0.30% of Cu and the balance being Fe and inevitable impurity elements. smelting raw materials are sequentially subjected to KR molten iron pretreatment, converter smelting, LF refining and RH vacuum degassing to obtain molten steel which is relatively high in purity, and then the pipeline steel, which is high in thickness, high in strength, narrow in strength interval, excellent in low-temperature toughness, and excellent in both low-temperature resistant aging performance and HIC resistance, is obtained through a controlled rolling and controlled cooling process.