Ultrahigh-strength steel and preparation method thereof

The invention relates to the technical field of ferrous metallurgy, and particularly discloses ultrahigh-strength steel and a preparation method thereof. The ultrahigh-strength steel comprises C, Mn, Si, Ni, Al, Cr and V, and S is limited to be smaller than or equal to 0.010%, P is limited to be smaller than or equal to 0.010%, H is limited to be smaller than or equal to 0.0001%, O is limited to be smaller than or equal to 0.0015%, and N is limited to be smaller than or equal to 0.010%. Through the synergistic effect of all chemical components, the mechanical property of the ultrahigh-strength steel is improved, and the prepared ultrahigh-strength steel has excellent strength and plasticity and has good industrial prospects and social benefits; meanwhile, harmful elements and residual elements are strictly controlled, so that the purity of the ultrahigh-strength steel is improved, and the ultrahigh-strength steel has good ductility, plasticity and strength. 本发明涉及钢铁冶金技术领域，具体公开一种超高强钢及其制备方法。本发明提供的超高强钢，包括C、Mn、Si、