Ultrahigh-strength X100 pipeline steel plate with excellent crack resistance and preparation method thereof

The invention discloses an ultrahigh-strength X100 pipeline steel plate with excellent crack resistance. The steel plate comprises the following chemical components: 0.03-0.06% of C, 0.20-0.50% of Si, 1.80-2.10% of Mn, no more than 0.005% of S, no more than 0.010% of P, 0.20-0.50% of Ni, 0.20-0.40% of Mo, 0.20-0.50% of Cr, 0.20-0.50% of Cu, 0.050-0.080% of Nb, 0.015-0.035% of Ti, no more than 0.004% of N, no more than 0.004% of O, no more than 0.002% of H, no less than 0.015% of Als and the balance of Fe and trace impurities; Pcm is no more than 0.25%. The invention also discloses a preparation method of the steel plate. A shock crack of a V-shaped gap of the steel plate can exceed 55J, the shock crack can expand over 160J, and the crack resistance is good.